Board to Board & Mezzanine Connectors

.hide-partial { max-height: none; } .show-more { display: none; }

Flexible Stacking Connectors

Samtec Flex Stacking Board Connectors feature a large variety of board-to-board connectors with design flexibility. These Samtec board-to-board connector systems are available in a variety of pitches, densities, stack heights, orientations, and other standard or modified options, making it easy to find the right connector for any application. Flex-Stack options include one-piece, low profile pass-through, elevated, hermaphroditic, shrouded, coplanar, parallel, and perpendicular. Post heights are adjustable in increments of 0.005” (0.13mm).

.catnav-wrapper { height: auto; overflow: visible; } .catalog-nav-tabs ul { white-space: normal; }

Results: 132,102

Applied Filters:

Product

Number of Positions

Pitch

Number of Rows

Termination Style

Mounting Angle

Stack Height

Current Rating

Voltage Rating

Maximum Data Rate

Minimum Operating Temperature

Maximum Operating Temperature

Contact Plating

Contact Material

Housing Material

Series

Packaging

Reset All

Search within results

In Stock

Normally Stocked

Active

New Products

RoHS Compliant

.search-refine-wrapper { display: inline-block; min-width: 100%; } .scroll-body { overflow-x: visible; } .search-table-wrapper { overflow: visible; } .hide-partial { max-height: none; } .show-more { display: none; }

Part #

Board to Board & Mezzanine Connectors 0.50 mm Edge Rate Rugged High Speed Terminal

ERM5-060-05.0-L-DV-K-TR
Samtec
1: $5.81
1,940In Stock

Mfr. Part No.
ERM5-060-05.0-L-DV-K-TR

Mouser Part No
200-ERM5060050LDVKTR

Samtec

Board to Board & Mezzanine Connectors 0.50 mm Edge Rate Rugged High Speed Terminal

Learn More

Datasheet

1,940In Stock

Cut Tape

$5.81

$5.32

$4.99

Reel

$4.50

$4.41

View

Min.: 1
Mult.: 1

Reel: 275

Headers

120 Position

0.5 mm (0.02 in)

2 Row

Solder

Vertical

10 mm, 12 mm

56 Gbps

- 55 C

+ 125 C

Gold

Phosphor Bronze

Liquid Crystal Polymer (LCP)

ERM5

Reel, Cut Tape

Board to Board & Mezzanine Connectors 0.635 mm Edge Rate Rugged High Speed Terminal

ERM6-50-01.5-L-DV-A-K-TR
Samtec
1: $8.62
615In Stock

Mfr. Part No.
ERM6-50-01.5-L-DV-A-K-TR

Mouser Part No
200-ERM650015LDVAKTR

Samtec

Board to Board & Mezzanine Connectors 0.635 mm Edge Rate Rugged High Speed Terminal

Learn More

Datasheet

615In Stock

Cut Tape

$8.62

$7.38

$6.83

$6.46

Reel

$4.65

View

Min.: 1
Mult.: 1

Reel: 675

Headers

100 Position

0.635 mm (0.025 in)

2 Row

Solder

Vertical

5 mm

56 Gbps

- 55 C

+ 125 C

Gold

Copper Alloy

Liquid Crystal Polymer (LCP)

ERM6

Reel, Cut Tape

Board to Board & Mezzanine Connectors 0.80 mm Edge Rate Rugged High Speed Terminal

ERM8-060-02.0-L-DV-TR
Samtec
1: $7.24
1,345In Stock

Mfr. Part No.
ERM8-060-02.0-L-DV-TR

Mouser Part No
200-ERM806002.0LDVTR

Samtec

Board to Board & Mezzanine Connectors 0.80 mm Edge Rate Rugged High Speed Terminal

Learn More

Datasheet

1,345In Stock

Cut Tape

$7.24

$6.54

$6.18

$5.99

Reel

$5.26

View

Min.: 1
Mult.: 1

Reel: 375

Headers

120 Position

0.8 mm (0.031 in)

2 Row

Solder

Vertical

7 mm, 9 mm, 11 mm

56 Gbps

- 55 C

+ 125 C

Gold

Phosphor Bronze

Liquid Crystal Polymer (LCP)

ERM8

Reel, Cut Tape

Board to Board & Mezzanine Connectors 1.00 mm One-Piece Interface

FSI-120-06-L-D-AD
Samtec
1: $9.48
192In Stock

Mfr. Part No.
FSI-120-06-L-D-AD

Mouser Part No
200-FSI12006LDAD

Samtec

Board to Board & Mezzanine Connectors 1.00 mm One-Piece Interface

Datasheet

192In Stock

$9.48

$8.76

$8.28

$7.98

View

Min.: 1
Mult.: 1

Connectors

40 Position

1.27 mm (0.05 in)

2 Row

Solder

Vertical

2.8 A

220 VAC

- 55 C

+ 125 C

Gold

Beryllium Copper

Liquid Crystal Polymer (LCP)

FSI

Tube

Board to Board & Mezzanine Connectors .050 LP Array High-Speed High-Density Low Profile Open-Pin-Field Array

LPAF-40-03.0-L-08-2-K-TR
Samtec
1: $27.33
582In Stock

Mfr. Part No.
LPAF-40-03.0-L-08-2-K-TR

Mouser Part No
200-LPAF40030L082KTR

Samtec

Board to Board & Mezzanine Connectors .050 LP Array High-Speed High-Density Low Profile Open-Pin-Field Array

Learn More

Datasheet

582In Stock

Cut Tape

$27.33

$26.13

$25.15

$23.31

Reel

$17.03

View

Min.: 1
Mult.: 1

Reel: 350

Sockets

320 Position

1.27 mm (0.05 in)

8 Row

Crimp

Vertical

4 mm, 4.5 mm

2.2 A

250 VAC

28 Gbps

- 55 C

+ 125 C

Gold

Copper Alloy

Liquid Crystal Polymer (LCP)

LPAF

Reel, Cut Tape

Board to Board & Mezzanine Connectors 0.50 mm Low Profile Blade & Beam Socket Strip

LSH-020-01-G-D-A-K-TR
Samtec
1: $3.30
826In Stock

Mfr. Part No.
LSH-020-01-G-D-A-K-TR

Mouser Part No
200-LSH02001GDAKTR

Samtec

Board to Board & Mezzanine Connectors 0.50 mm Low Profile Blade & Beam Socket Strip

Learn More

Datasheet

826In Stock

Cut Tape

$3.30

$3.03

$2.84

$2.56

Reel

$2.18

View

MouseReel Available

Min.: 1
Mult.: 1

Reel: 950

Sockets

40 Position

0.5 mm (0.02 in)

2 Row

Solder

Vertical

2.31 mm

2.6 A

188 VAC

- 55 C

+ 125 C

Gold

Beryllium Copper

Liquid Crystal Polymer (LCP)

LSH

Reel, Cut Tape, MouseReel

Board to Board & Mezzanine Connectors 0.635 mm Razor Beam High-Speed Hermaphroditic Terminal/Socket Strip

LSS-110-02-F-DV-A
Samtec
1: $3.00
1,367In Stock

Mfr. Part No.
LSS-110-02-F-DV-A

Mouser Part No
200-LSS11002FDVA

Samtec

Board to Board & Mezzanine Connectors 0.635 mm Razor Beam High-Speed Hermaphroditic Terminal/Socket Strip

Datasheet

1,367In Stock

$3.00

$2.53

$2.20

$1.87

View

Min.: 1
Mult.: 1

Connectors

20 Position

0.635 mm (0.025 in)

2 Row

Solder

Vertical

9 mm, 10 mm, 12 mm

1.7 A

300 VAC

25 Gbps

- 55 C

+ 125 C

Gold

Phosphor Bronze

Liquid Crystal Polymer (LCP)

LSS

Tray

Board to Board & Mezzanine Connectors 0.50 mm Low Profile Blade & Beam Terminal Strip

LTH-020-01-G-D-A-K-TR
Samtec
1: $3.26
1,559In Stock

Mfr. Part No.
LTH-020-01-G-D-A-K-TR

Mouser Part No
200-LTH02001GDAKTR

Samtec

Board to Board & Mezzanine Connectors 0.50 mm Low Profile Blade & Beam Terminal Strip

Learn More

Datasheet

1,559In Stock

Cut Tape

$3.26

$2.92

$2.63

$2.51

Reel

$2.11

View

MouseReel Available

Min.: 1
Mult.: 1

Reel: 900

Headers

40 Position

0.5 mm (0.02 in)

2 Row

Solder

Vertical

2.31 mm

2.6 A

188 VAC

- 55 C

+ 125 C

Gold

Beryllium Copper

Liquid Crystal Polymer (LCP)

LTH

Reel, Cut Tape, MouseReel

Board to Board & Mezzanine Connectors 0.80 mm Q Rate Slim Body Ground Plane Socket

QRF8-026-01-L-RA-GP
Samtec
1: $16.84
365In Stock

Mfr. Part No.
QRF8-026-01-L-RA-GP

Mouser Part No
200-QRF802601LRAGP

Samtec

Board to Board & Mezzanine Connectors 0.80 mm Q Rate Slim Body Ground Plane Socket

Learn More

Datasheet

365In Stock

$16.84

$13.74

$12.71

$10.64

Quote

Min.: 1
Mult.: 1

Sockets

52 Position

0.8 mm (0.031 in)

2 Row

Solder

Right Angle

2.2 A

215 VAC

28 Gbps

- 55 C

+ 125 C

Gold

Beryllium Copper

Liquid Crystal Polymer (LCP)

QRF8

Tray

Board to Board & Mezzanine Connectors 0.80 mm Q Rate Slim Body Ground Plane Header

QRM8-026-05.0-L-D-A-GP
Samtec
1: $10.41
392In Stock

Mfr. Part No.
QRM8-026-05.0-L-D-A-GP

Mouser Part No
200-QRM802605.0LDAGP

Samtec

Board to Board & Mezzanine Connectors 0.80 mm Q Rate Slim Body Ground Plane Header

Learn More

Datasheet

392In Stock

$10.41

$7.86

$6.58

Quote

Min.: 1
Mult.: 1

Headers

52 Position

0.8 mm (0.031 in)

2 Row

Solder

Straight

10 mm, 12 mm

2.2 A

215 VAC

28 Gbps

- 55 C

+ 125 C

Gold

Phosphor Bronze

Liquid Crystal Polymer (LCP)

QRM8

Tray

Board to Board & Mezzanine Connectors 0.80 mm Q Rate Slim Body Ground Plane Header

QRM8-052-07.0-L-D-A-GP
Samtec
1: $17.50
106In Stock

Mfr. Part No.
QRM8-052-07.0-L-D-A-GP

Mouser Part No
200-QRM805207.0LDAGP

Samtec

Board to Board & Mezzanine Connectors 0.80 mm Q Rate Slim Body Ground Plane Header

Learn More

Datasheet

106In Stock

$17.50

$16.51

$15.84

$15.56

View

Min.: 1
Mult.: 1

Headers

104 Position

0.8 mm (0.031 in)

2 Row

Solder

Straight

12 mm, 14 mm

2.2 A

215 VAC

28 Gbps

- 55 C

+ 125 C

Gold

Phosphor Bronze

Liquid Crystal Polymer (LCP)

QRM8

Tray

Board to Board & Mezzanine Connectors 0.50 mm Q Strip High-Speed Ground Plane Socket Strip

QSH-020-01-C-D-DP-A-K
Samtec
1: $13.73
136In Stock

Mfr. Part No.
QSH-020-01-C-D-DP-A-K

Mouser Part No
200-QSH02001CDDPAK

Samtec

Board to Board & Mezzanine Connectors 0.50 mm Q Strip High-Speed Ground Plane Socket Strip

Learn More

Datasheet

136In Stock

$13.73

$11.40

$9.07

Quote

Min.: 1
Mult.: 1

Sockets

40 Position

0.5 mm (0.02 in)

2 Row

Solder

Straight

2 A

175 VAC

- 55 C

+ 125 C

Gold

Phosphor Bronze

Liquid Crystal Polymer (LCP)

QSH

Tray

Board to Board & Mezzanine Connectors 0.50 mm Q Strip High-Speed Ground Plane Socket Strip

QSH-030-01-F-D-A-K-TR
Samtec
1: $4.96
2,069In Stock

Mfr. Part No.
QSH-030-01-F-D-A-K-TR

Mouser Part No
200-QSH03001FDAKTR

Samtec

Board to Board & Mezzanine Connectors 0.50 mm Q Strip High-Speed Ground Plane Socket Strip

Learn More

Datasheet

2,069In Stock

Cut Tape

$4.96

$4.54

$4.26

$3.84

Reel

$3.61

View

MouseReel Available

Min.: 1
Mult.: 1

Reel: 525

Sockets

60 Position

0.5 mm (0.02 in)

2 Row

Solder

Straight

2 A

175 VAC

- 55 C

+ 125 C

Gold

Phosphor Bronze

Liquid Crystal Polymer (LCP)

QSH

Reel, Cut Tape, MouseReel

Board to Board & Mezzanine Connectors 0.50 mm Q Strip High-Speed Ground Plane Socket Strip

QSH-060-01-C-D-A-K
Samtec
1: $8.18
315In Stock

Mfr. Part No.
QSH-060-01-C-D-A-K

Mouser Part No
200-QSH06001CDAK

Samtec

Board to Board & Mezzanine Connectors 0.50 mm Q Strip High-Speed Ground Plane Socket Strip

Learn More

Datasheet

315In Stock

$8.18

$7.05

$6.66

$6.25

Quote

Min.: 1
Mult.: 1

Sockets

120 Position

0.5 mm (0.02 in)

2 Row

Solder

Straight

2 A

175 VAC

- 55 C

+ 125 C

Gold

Phosphor Bronze

Liquid Crystal Polymer (LCP)

QSH

Tray

Board to Board & Mezzanine Connectors 0.50 mm Q Strip High-Speed Ground Plane Socket Strip

QSH-150-01-L-D-A
Samtec
1: $19.84
116In Stock

Mfr. Part No.
QSH-150-01-L-D-A

Mouser Part No
200-QSH15001LDA

Samtec

Board to Board & Mezzanine Connectors 0.50 mm Q Strip High-Speed Ground Plane Socket Strip

Learn More

Datasheet

116In Stock

$19.84

$19.26

$18.77

$15.23

View

Min.: 1
Mult.: 1

Sockets

300 Position

0.5 mm (0.02 in)

2 Row

Solder

Straight

2 A

175 VAC

- 55 C

+ 125 C

Gold

Phosphor Bronze

Liquid Crystal Polymer (LCP)

QSH

Tray

Board to Board & Mezzanine Connectors Q Strip High-Speed Ground Plane Header

QTE-014-01-L-D-DP-A
Samtec
1: $6.11
480In Stock

Mfr. Part No.
QTE-014-01-L-D-DP-A

Mouser Part No
200-QTE01401LDDPA

Samtec

Board to Board & Mezzanine Connectors Q Strip High-Speed Ground Plane Header

Learn More

Datasheet

480In Stock

$6.11

$4.68

$4.20

$3.24

$2.28

Min.: 1
Mult.: 1

Connectors

28 Position

0.8 mm (0.031 in)

2 Row

Solder

Straight

5 mm

2 A

225 VAC

- 55 C

+ 125 C

Gold

Phosphor Bronze

Liquid Crystal Polymer (LCP)

QTE

Tray

Board to Board & Mezzanine Connectors Q Strip High-Speed Ground Plane Header

QTE-020-04-F-D-A
Samtec
1: $9.65
544In Stock

Mfr. Part No.
QTE-020-04-F-D-A

Mouser Part No
200-QTE02004FDA

Samtec

Board to Board & Mezzanine Connectors Q Strip High-Speed Ground Plane Header

Learn More

Datasheet

544In Stock

$9.65

$7.11

$6.39

$4.93

Quote

Min.: 1
Mult.: 1

Headers

40 Position

0.8 mm (0.031 in)

2 Row

Solder

Vertical

16 mm

2 A

225 VAC

28 Gbps

- 55 C

+ 125 C

Gold

Phosphor Bronze

Liquid Crystal Polymer (LCP)

QTE

Tray

Board to Board & Mezzanine Connectors 0.50 mm Q Strip High-Speed Ground Plane Terminal Strip

QTH-020-04-L-D-DP-A
Samtec
1: $15.26
390In Stock

Mfr. Part No.
QTH-020-04-L-D-DP-A

Mouser Part No
200-QTH02004LDDPA

Samtec

Board to Board & Mezzanine Connectors 0.50 mm Q Strip High-Speed Ground Plane Terminal Strip

Learn More

Datasheet

390In Stock

$15.26

$11.54

$10.42

$8.19

Quote

Min.: 1
Mult.: 1

Headers

40 Position

0.5 mm (0.02 in)

2 Row

Solder Pin

Vertical

16 mm

2 A

175 VAC

25 Gbps

- 55 C

+ 125 C

Gold

Phosphor Bronze

Liquid Crystal Polymer (LCP)

QTH

Tray

Board to Board & Mezzanine Connectors 0.50 mm Q Strip High-Speed Ground Plane Terminal Strip

QTH-120-07-L-D-A
Samtec
1: $30.25
55In Stock

Mfr. Part No.
QTH-120-07-L-D-A

Mouser Part No
200-QTH12007LDA

Samtec

Board to Board & Mezzanine Connectors 0.50 mm Q Strip High-Speed Ground Plane Terminal Strip

Learn More

Datasheet

55In Stock

$30.25

$29.36

$27.23

$23.22

View

Min.: 1
Mult.: 1

Headers

240 Position

0.5 mm (0.02 in)

2 Row

Solder

Straight

25 mm

2 A

175 VAC

- 55 C

+ 125 C

Gold

Phosphor Bronze

Liquid Crystal Polymer (LCP)

QTH

Tray

Board to Board & Mezzanine Connectors 0.635 mm Q Strip High-Speed Ground Plane Terminal Strip

QTS-025-02-L-D-A
Samtec
1: $8.52
186In Stock

Mfr. Part No.
QTS-025-02-L-D-A

Mouser Part No
200-QTS02502LDA

Samtec

Board to Board & Mezzanine Connectors 0.635 mm Q Strip High-Speed Ground Plane Terminal Strip

Learn More

Datasheet

186In Stock

$8.52

$6.28

$5.64

$4.35

Quote

Min.: 1
Mult.: 1

Headers

50 Position

0.635 mm (0.025 in)

2 Row

Solder

Straight

1.8 A

285 VAC

- 55 C

+ 125 C

Gold

Phosphor Bronze

Liquid Crystal Polymer (LCP)

QTS

Tray

Board to Board & Mezzanine Connectors 0.635 mm Q Strip High-Speed Ground Plane Terminal Strip

QTS-050-01-L-D-A-K-TR
Samtec
1: $6.15
348In Stock

Mfr. Part No.
QTS-050-01-L-D-A-K-TR

Mouser Part No
200-QTS05001LDAKTR

Samtec

Board to Board & Mezzanine Connectors 0.635 mm Q Strip High-Speed Ground Plane Terminal Strip

Learn More

Datasheet

348In Stock

Cut Tape

$6.15

$5.67

$5.32

Reel

$4.68

$4.41

View

Min.: 1
Mult.: 1

Reel: 425

Headers

100 Position

0.635 mm (0.025 in)

2 Row

Solder

Straight

1.8 A

285 VAC

- 55 C

+ 125 C

Gold

Phosphor Bronze

Liquid Crystal Polymer (LCP)

QTS

Reel, Cut Tape

Board to Board & Mezzanine Connectors 1.00 mm SATALink Compatible High-Speed Micro Plane Socket

SAL1-140-01-S-S-A-TR
Samtec
1: $16.52
286In Stock

Mfr. Part No.
SAL1-140-01-S-S-A-TR

Mouser Part No
200-SAL114001SSATR

Samtec

Board to Board & Mezzanine Connectors 1.00 mm SATALink Compatible High-Speed Micro Plane Socket

Datasheet

286In Stock

Cut Tape

$16.52

$14.89

$13.27

$10.83

Reel

$7.82

View

Min.: 1
Mult.: 1

Reel: 400

Connectors

40 Position

1 mm (0.039 in)

Solder

Right Angle

2.9 A

- 55 C

+ 125 C

Gold

Beryllium Copper

Liquid Crystal Polymer (LCP)

SAL1

Reel, Cut Tape

Board to Board & Mezzanine Connectors .050 SEARAY High-Speed High-Density Open-Pin-Field Array Socket

SEAF-30-05.0-S-04-2-A-K-TR
Samtec
1: $13.42
498In Stock

Mfr. Part No.
SEAF-30-05.0-S-04-2-A-K-TR

Mouser Part No
200-SEAF3005.0S042AK

Samtec

Board to Board & Mezzanine Connectors .050 SEARAY High-Speed High-Density Open-Pin-Field Array Socket

Learn More

Datasheet

498In Stock

Cut Tape

$13.42

$12.84

$12.35

$11.45

Reel

$8.37

View

Min.: 1
Mult.: 1

Reel: 375

Sockets

120 Position

1.27 mm (0.05 in)

4 Row

Solder

Vertical

7 mm, 8 mm, 8.5 mm, 11.5 mm, 12 mm, 14 mm, 16 mm

2.7 A

240 VAC

56 Gbps

- 55 C

+ 125 C

Gold

Copper Alloy

Liquid Crystal Polymer (LCP)

SEAF

Reel, Cut Tape

Board to Board & Mezzanine Connectors .050 SEARAY High-Speed High-Density Open-Pin-Field Array Terminal

SEAM-20-07.0-S-04-2-A-K-TR
Samtec
1: $17.08
150In Stock

Mfr. Part No.
SEAM-20-07.0-S-04-2-A-K-TR

Mouser Part No
200-SEAM2007.0S042AK

Samtec

Board to Board & Mezzanine Connectors .050 SEARAY High-Speed High-Density Open-Pin-Field Array Terminal

Learn More

Datasheet

150In Stock

Cut Tape

$17.08

$16.34

$15.72

$14.57

Reel

$12.52

View

Min.: 1
Mult.: 1

Reel: 150

Headers

160 Position

1.27 mm (0.05 in)

4 Row

Solder

Vertical

12 mm, 13 mm, 13.5 mm, 14.5 mm

2.7 A

240 VAC

56 Gbps

- 55 C

+ 125 C

Gold

Copper Alloy

Liquid Crystal Polymer (LCP)

SEAM

Reel, Cut Tape

Board to Board & Mezzanine Connectors .050 SEARAY High-Speed High-Density Open-Pin-Field Array Terminal

SEAM-30-02.0-L-10-2-A-K-TR
Samtec
1: $22.70
279In Stock

Mfr. Part No.
SEAM-30-02.0-L-10-2-A-K-TR

Mouser Part No
200-SEAM3002.0L102AK

Samtec

Board to Board & Mezzanine Connectors .050 SEARAY High-Speed High-Density Open-Pin-Field Array Terminal

Learn More

Datasheet

279In Stock

Cut Tape

$22.70

$21.71

$20.89

$19.37

Reel

$16.64

View

Min.: 1
Mult.: 1

Reel: 225

Headers

300 Position

1.27 mm (0.05 in)

10 Row

Solder

Vertical

7 mm, 8 mm, 8.5 mm, 9.5 mm

2.7 A

240 VAC

56 Gbps

- 55 C

+ 125 C

Gold

Copper Alloy

Liquid Crystal Polymer (LCP)

SEAM

Reel, Cut Tape

Flexible Stacking Connectors

Customer Service Office

Company

Resources

Support

1 Position
2 Position
3 Position
4 Position
5 Position
6 Position
7 Position
8 Position
9 Position
10 Position
11 Position
12 Position
13 Position
14 Position
15 Position
16 Position
17 Position
18 Position
19 Position
20 Position

0.314 mm
0.393 mm
0.433 mm
0.472 mm
0.511 mm
0.551 mm
0.590 mm
0.629 mm
0.708 mm
0.748 mm
0.787 mm
0.826 mm
0.866 mm
0.905 mm
0.944 mm
0.984 mm
1.023 mm
1.062 mm
1.102 mm
1.141 mm

400 mA
1 A
1.1 A
1.2 A
1.3 A
1.34 A
1.4 A
1.5 A
1.6 A
1.7 A
1.8 A
1.8 A, 23.1 A
1.9 A
2 A
2 A, 23 A
2 A, 25 A
2.1 A
2.1 A, 9.6 A
2.2 A
2.2 A, 8.5 A

120 VAC
125 V
125 VAC
150 VAC
150 VAC, 212 VDC
150 VAC/212 VDC
155 V
155 VAC
155 VAC, 219 VDC
160 VAC
175 V
175 VAC
180 VAC
188 VAC
190 VAC, 269 VDC
195 V
200 VAC
210 VAC
215 V
215 VAC

A-TW-SM
ADF6
ADM6
AMF6
APF6
APM6
ASP
AW
BSE
BSH
BSS
BSW
BTE
BTH
BTS
CLM
DVM
DW
DWM
ERF5