Skip to content

Foster

Foster quick couplers set the standard in pneumatic and hydraulic connections. Part of the ZSI-Foster line, Foster couplers and plugs cover the full range of industrial interchanges and body sizes in steel, brass, and stainless construction. Built for reliable, repeatable connections in air and fluid systems. Shop the full Foster range below.

Filters

Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass Save 20% Save %
$ 14.39
$ 14.39 - $ 14.39
$ 14.39
$ 11.49
$ 11.49 - $ 11.49
$ 11.49

Foster PD9-4, 3/8" Industrial Plug x Reusable Hose Fitting, 3/8" ID x 11/16" OD, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster PD9-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-fl...

View full details
$ 14.39
$ 14.39 - $ 14.39
$ 14.39
$ 11.49
$ 11.49 - $ 11.49
$ 11.49
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass Save 20% Save %
$ 14.29
$ 14.29 - $ 14.29
$ 14.29
$ 11.39
$ 11.39 - $ 11.39
$ 11.39

Foster PD7-4, 3/8" Industrial Plug x Reusable Hose Fitting, 3/8" ID x 5/8" OD, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster PD7-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-fl...

View full details
$ 14.29
$ 14.29 - $ 14.29
$ 14.29
$ 11.39
$ 11.39 - $ 11.39
$ 11.39
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass Save 20% Save %
$ 15.79
$ 15.79 - $ 15.79
$ 15.79
$ 12.69
$ 12.69 - $ 12.69
$ 12.69

Foster PB7-4, 3/8" Industrial Plug x Reusable Hose Fitting, 1/4" ID x 5/8" OD, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster PB7-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-fl...

View full details
$ 15.79
$ 15.79 - $ 15.79
$ 15.79
$ 12.69
$ 12.69 - $ 12.69
$ 12.69
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass Save 20% Save %
$ 13.89
$ 13.89 - $ 13.89
$ 13.89
$ 11.09
$ 11.09 - $ 11.09
$ 11.09

Foster PB5-4, 3/8" Industrial Plug x Reusable Hose Fitting, 1/4" ID x 9/16" OD, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster PB5-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-fl...

View full details
$ 13.89
$ 13.89 - $ 13.89
$ 13.89
$ 11.09
$ 11.09 - $ 11.09
$ 11.09
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 14.89
$ 14.89 - $ 14.89
$ 14.89
$ 11.89
$ 11.89 - $ 11.89
$ 11.89

Foster PB3-4, 3/8" Industrial Plug x Reusable Hose Fitting, 1/4" ID x 1/2" OD, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster PB3-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-fl...

View full details
$ 14.89
$ 14.89 - $ 14.89
$ 14.89
$ 11.89
$ 11.89 - $ 11.89
$ 11.89
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 19% Save %
$ 10.79
$ 10.79 - $ 10.79
$ 10.79
$ 8.69
$ 8.69 - $ 8.69
$ 8.69

Foster 81-4, 3/8" Industrial Plug x 1/2" Push-On Hose Stem, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 81-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-flo...

View full details
$ 10.79
$ 10.79 - $ 10.79
$ 10.79
$ 8.69
$ 8.69 - $ 8.69
$ 8.69
Save 19% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 26.89
$ 26.89 - $ 26.89
$ 26.89
$ 21.49
$ 21.49 - $ 21.49
$ 21.49

Foster 71-4B, 3/8" Industrial Plug x 3/8" Push-On Hose Stem, 4 Series, Brass

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 71-4B is a Brass 3/8" industrial plug from the Foster 4 Series — a high-fl...

View full details
$ 26.89
$ 26.89 - $ 26.89
$ 26.89
$ 21.49
$ 21.49 - $ 21.49
$ 21.49
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 6.39
$ 6.39 - $ 6.39
$ 6.39
$ 5.09
$ 5.09 - $ 5.09
$ 5.09

Foster 71-4, 3/8" Industrial Plug x 3/8" Push-On Hose Stem, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 71-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-flo...

View full details
$ 6.39
$ 6.39 - $ 6.39
$ 6.39
$ 5.09
$ 5.09 - $ 5.09
$ 5.09
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 19% Save %
$ 7.39
$ 7.39 - $ 7.39
$ 7.39
$ 5.99
$ 5.99 - $ 5.99
$ 5.99

Foster 51-4, 3/8" Industrial Plug x 1/4" Push-On Hose Stem, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 51-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-flo...

View full details
$ 7.39
$ 7.39 - $ 7.39
$ 7.39
$ 5.99
$ 5.99 - $ 5.99
$ 5.99
Save 19% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 6.99
$ 6.99 - $ 6.99
$ 6.99
$ 5.59
$ 5.59 - $ 5.59
$ 5.59

Foster 49-4, 3/8" Industrial Plug x 1/2" Hose ID, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 49-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-flo...

View full details
$ 6.99
$ 6.99 - $ 6.99
$ 6.99
$ 5.59
$ 5.59 - $ 5.59
$ 5.59
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 19% Save %
$ 9.89
$ 9.89 - $ 9.89
$ 9.89
$ 7.99
$ 7.99 - $ 7.99
$ 7.99

Foster 48-4B, 3/8" Industrial Plug x 3/8" Hose ID, 4 Series, Brass

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 48-4B is a Brass 3/8" industrial plug from the Foster 4 Series — a high-fl...

View full details
$ 9.89
$ 9.89 - $ 9.89
$ 9.89
$ 7.99
$ 7.99 - $ 7.99
$ 7.99
Save 19% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 21% Save %
$ 6.29
$ 6.29 - $ 6.29
$ 6.29
$ 4.99
$ 4.99 - $ 4.99
$ 4.99

Foster 48-4, 3/8" Industrial Plug x 3/8" Hose ID, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 48-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-flo...

View full details
$ 6.29
$ 6.29 - $ 6.29
$ 6.29
$ 4.99
$ 4.99 - $ 4.99
$ 4.99
Save 21% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 10.39
$ 10.39 - $ 10.39
$ 10.39
$ 8.29
$ 8.29 - $ 8.29
$ 8.29

Foster 47-4, 3/8" Industrial Plug x 5/16" Hose ID, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 47-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-flo...

View full details
$ 10.39
$ 10.39 - $ 10.39
$ 10.39
$ 8.29
$ 8.29 - $ 8.29
$ 8.29
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 8.79
$ 8.79 - $ 8.79
$ 8.79
$ 6.99
$ 6.99 - $ 6.99
$ 6.99

Foster 46-4, 3/8" Industrial Plug x 1/4" Hose ID, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 46-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-flo...

View full details
$ 8.79
$ 8.79 - $ 8.79
$ 8.79
$ 6.99
$ 6.99 - $ 6.99
$ 6.99
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 17.19
$ 17.19 - $ 17.19
$ 17.19
$ 13.69
$ 13.69 - $ 13.69
$ 13.69

Foster 44S-4, 3/8" Industrial Plug x 1/2" Male NPT, 4 Series, Free Swivel, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 44S-4 is a Brass/Steel 3/8" industrial plug from the Foster 4 Series — a h...

View full details
$ 17.19
$ 17.19 - $ 17.19
$ 17.19
$ 13.69
$ 13.69 - $ 13.69
$ 13.69
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 12.99
$ 12.99 - $ 12.99
$ 12.99
$ 10.39
$ 10.39 - $ 10.39
$ 10.39

Foster 42S-4, 3/8" Industrial Plug x 3/8" Male NPT, 4 Series, Free Swivel, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 42S-4 is a Brass/Steel 3/8" industrial plug from the Foster 4 Series — a h...

View full details
$ 12.99
$ 12.99 - $ 12.99
$ 12.99
$ 10.39
$ 10.39 - $ 10.39
$ 10.39
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 20.09
$ 20.09 - $ 20.09
$ 20.09
$ 16.09
$ 16.09 - $ 16.09
$ 16.09

Foster 40S-4, 3/8" Industrial Plug x 1/4" Male NPT, 4 Series, Free Swivel, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 40S-4 is a Brass/Steel 3/8" industrial plug from the Foster 4 Series — a h...

View full details
$ 20.09
$ 20.09 - $ 20.09
$ 20.09
$ 16.09
$ 16.09 - $ 16.09
$ 16.09
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 6.99
$ 6.99 - $ 6.99
$ 6.99
$ 5.59
$ 5.59 - $ 5.59
$ 5.59

Foster 44-4, 3/8" Industrial Plug x 1/2" Male NPT, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 44-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-flo...

View full details
$ 6.99
$ 6.99 - $ 6.99
$ 6.99
$ 5.59
$ 5.59 - $ 5.59
$ 5.59
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 14.49
$ 14.49 - $ 14.49
$ 14.49
$ 11.59
$ 11.59 - $ 11.59
$ 11.59

Foster 42-4S/S, 3/8" Industrial Plug x 3/8" Male NPT, 4 Series, 303 Stainless

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 42-4S/S is a 303 Stainless 3/8" industrial plug from the Foster 4 Series —...

View full details
$ 14.49
$ 14.49 - $ 14.49
$ 14.49
$ 11.59
$ 11.59 - $ 11.59
$ 11.59
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 8.99
$ 8.99 - $ 8.99
$ 8.99
$ 7.19
$ 7.19 - $ 7.19
$ 7.19

Foster 42-4B, 3/8" Industrial Plug x 3/8" Male NPT, 4 Series, Brass

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 42-4B is a Brass 3/8" industrial plug from the Foster 4 Series — a high-fl...

View full details
$ 8.99
$ 8.99 - $ 8.99
$ 8.99
$ 7.19
$ 7.19 - $ 7.19
$ 7.19
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 10.49
$ 10.49 - $ 10.49
$ 10.49
$ 8.39
$ 8.39 - $ 8.39
$ 8.39

Foster 40-4S/S, 3/8" Industrial Plug x 1/4" Male NPT, 4 Series, 303 Stainless

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 40-4S/S is a 303 Stainless 3/8" industrial plug from the Foster 4 Series —...

View full details
$ 10.49
$ 10.49 - $ 10.49
$ 10.49
$ 8.39
$ 8.39 - $ 8.39
$ 8.39
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 21% Save %
$ 9.19
$ 9.19 - $ 9.19
$ 9.19
$ 7.29
$ 7.29 - $ 7.29
$ 7.29

Foster 40-4B, 3/8" Industrial Plug x 1/4" Male NPT, 4 Series, Brass

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 40-4B is a Brass 3/8" industrial plug from the Foster 4 Series — a high-fl...

View full details
$ 9.19
$ 9.19 - $ 9.19
$ 9.19
$ 7.29
$ 7.29 - $ 7.29
$ 7.29
Save 21% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 5.39
$ 5.39 - $ 5.39
$ 5.39
$ 4.29
$ 4.29 - $ 4.29
$ 4.29

Foster 40-4, 3/8" Industrial Plug x 1/4" Male NPT, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 40-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-flo...

View full details
$ 5.39
$ 5.39 - $ 5.39
$ 5.39
$ 4.29
$ 4.29 - $ 4.29
$ 4.29
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 11.39
$ 11.39 - $ 11.39
$ 11.39
$ 9.09
$ 9.09 - $ 9.09
$ 9.09

Foster 38-4, 3/8" Industrial Plug x 1/8" Male NPT, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 38-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-flo...

View full details
$ 11.39
$ 11.39 - $ 11.39
$ 11.39
$ 9.09
$ 9.09 - $ 9.09
$ 9.09
Save 20% Save %

Request a Quote

Bulk and dealer pricing. Tell us what you need and we’ll reply within one business day.