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Foster 3 Series Couplers

The Foster 3 Series is the 1/4" body industrial interchange, the most popular air coupler size for shop and industrial systems. This collection includes 3 Series couplers and plugs in brass, steel, and stainless with NPT, hose barb, push-on, and reusable terminations, plus automatic, sleeve guard, ball check, and dust cap options. Filter by thread, material, and coupler or plug to match your line.

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Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass Save 20% Save %
$ 327.00
$ 327.00 - $ 327.00
$ 327.00
$ 263.00
$ 263.00 - $ 263.00
$ 263.00

Foster 3103S, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Steam/EPDM, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3103S is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — the...

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$ 327.00
$ 327.00 - $ 327.00
$ 327.00
$ 263.00
$ 263.00 - $ 263.00
$ 263.00
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Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass Save 20% Save %
$ 244.00
$ 244.00 - $ 244.00
$ 244.00
$ 195.00
$ 195.00 - $ 195.00
$ 195.00

Foster 3103LV, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Less Valve, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3103LV is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series —...

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$ 244.00
$ 244.00 - $ 244.00
$ 244.00
$ 195.00
$ 195.00 - $ 195.00
$ 195.00
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Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass Save 20% Save %
$ 287.00
$ 287.00 - $ 287.00
$ 287.00
$ 231.00
$ 231.00 - $ 231.00
$ 231.00

Foster 3103H, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Heat/Viton, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3103H is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — ...

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$ 287.00
$ 287.00 - $ 287.00
$ 287.00
$ 231.00
$ 231.00 - $ 231.00
$ 231.00
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Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass Save 20% Save %
$ 301.00
$ 301.00 - $ 301.00
$ 301.00
$ 240.00
$ 240.00 - $ 240.00
$ 240.00

Foster BL3103, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL3103 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series —...

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$ 301.00
$ 301.00 - $ 301.00
$ 301.00
$ 240.00
$ 240.00 - $ 240.00
$ 240.00
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Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 257.00
$ 257.00 - $ 257.00
$ 257.00
$ 206.00
$ 206.00 - $ 206.00
$ 206.00

Foster 3103, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3103 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — t...

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$ 257.00
$ 257.00 - $ 257.00
$ 257.00
$ 206.00
$ 206.00 - $ 206.00
$ 206.00
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Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 1,459.00
$ 1,459.00 - $ 1,459.00
$ 1,459.00
$ 1,166.00
$ 1,166.00 - $ 1,166.00
$ 1,166.00

Foster BL2903S/S, 1/4" Industrial Coupler x 1/8" Male NPT, 3 Series, Ball Lock, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL2903S/S is a 303 Stainless 1/4" industrial coupler from the Foster 3 Ser...

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$ 1,459.00
$ 1,459.00 - $ 1,459.00
$ 1,459.00
$ 1,166.00
$ 1,166.00 - $ 1,166.00
$ 1,166.00
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 %
$ 1,366.00
$ 1,366.00 - $ 1,366.00
$ 1,366.00
$ 1,092.00
$ 1,092.00 - $ 1,092.00
$ 1,092.00

Foster 2903S/S, 1/4" Industrial Coupler x 1/8" Male NPT, 3 Series, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 2903S/S is a 303 Stainless 1/4" industrial coupler from the Foster 3 Serie...

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$ 1,366.00
$ 1,366.00 - $ 1,366.00
$ 1,366.00
$ 1,092.00
$ 1,092.00 - $ 1,092.00
$ 1,092.00
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 %
$ 374.00
$ 374.00 - $ 374.00
$ 374.00
$ 299.00
$ 299.00 - $ 299.00
$ 299.00

Foster 2903S, 1/4" Industrial Coupler x 1/8" Male NPT, 3 Series, Steam/EPDM, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 2903S is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — the...

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$ 374.00
$ 374.00 - $ 374.00
$ 374.00
$ 299.00
$ 299.00 - $ 299.00
$ 299.00
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 %
$ 350.00
$ 350.00 - $ 350.00
$ 350.00
$ 280.00
$ 280.00 - $ 280.00
$ 280.00

Foster 2903H, 1/4" Industrial Coupler x 1/8" Male NPT, 3 Series, Heat/Viton, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 2903H is a Steel 1/4" industrial coupler from the Foster 3 Series — the mo...

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$ 350.00
$ 350.00 - $ 350.00
$ 350.00
$ 280.00
$ 280.00 - $ 280.00
$ 280.00
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 %
$ 339.00
$ 339.00 - $ 339.00
$ 339.00
$ 270.00
$ 270.00 - $ 270.00
$ 270.00

Foster BL2903, 1/4" Industrial Coupler x 1/8" Male NPT, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL2903 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series —...

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$ 339.00
$ 339.00 - $ 339.00
$ 339.00
$ 270.00
$ 270.00 - $ 270.00
$ 270.00
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 %
$ 310.00
$ 310.00 - $ 310.00
$ 310.00
$ 250.00
$ 250.00 - $ 250.00
$ 250.00

Foster 2903, 1/4" Industrial Coupler x 1/8" Male NPT, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 2903 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — t...

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$ 310.00
$ 310.00 - $ 310.00
$ 310.00
$ 250.00
$ 250.00 - $ 250.00
$ 250.00
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 %
$ 359.00
$ 359.00 - $ 359.00
$ 359.00
$ 287.00
$ 287.00 - $ 287.00
$ 287.00

Foster 3203W, 1/4" Industrial Coupler x 3/8" Female NPT, 3 Series, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3203W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — the...

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$ 359.00
$ 359.00 - $ 359.00
$ 359.00
$ 287.00
$ 287.00 - $ 287.00
$ 287.00
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 %
$ 1,278.00
$ 1,278.00 - $ 1,278.00
$ 1,278.00
$ 1,022.00
$ 1,022.00 - $ 1,022.00
$ 1,022.00

Foster 3203S/SLV, 1/4" Industrial Coupler x 3/8" Female NPT, 3 Series, Less Valve, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3203S/SLV is a 303 Stainless 1/4" industrial coupler from the Foster 3 Ser...

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$ 1,278.00
$ 1,278.00 - $ 1,278.00
$ 1,278.00
$ 1,022.00
$ 1,022.00 - $ 1,022.00
$ 1,022.00
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 %
$ 1,366.00
$ 1,366.00 - $ 1,366.00
$ 1,366.00
$ 1,092.00
$ 1,092.00 - $ 1,092.00
$ 1,092.00

Foster BL3203S/S, 1/4" Industrial Coupler x 3/8" Female NPT, 3 Series, Ball Lock, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL3203S/S is a 303 Stainless 1/4" industrial coupler from the Foster 3 Ser...

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$ 1,366.00
$ 1,366.00 - $ 1,366.00
$ 1,366.00
$ 1,092.00
$ 1,092.00 - $ 1,092.00
$ 1,092.00
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 %
$ 1,255.00
$ 1,255.00 - $ 1,255.00
$ 1,255.00
$ 1,004.00
$ 1,004.00 - $ 1,004.00
$ 1,004.00

Foster 3203S/S, 1/4" Industrial Coupler x 3/8" Female NPT, 3 Series, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3203S/S is a 303 Stainless 1/4" industrial coupler from the Foster 3 Serie...

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$ 1,255.00
$ 1,255.00 - $ 1,255.00
$ 1,255.00
$ 1,004.00
$ 1,004.00 - $ 1,004.00
$ 1,004.00
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 %
$ 269.00
$ 269.00 - $ 269.00
$ 269.00
$ 216.00
$ 216.00 - $ 216.00
$ 216.00

Foster 3203LV, 1/4" Industrial Coupler x 3/8" Female NPT, 3 Series, Less Valve, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3203LV is a Steel 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 269.00
$ 269.00 - $ 269.00
$ 269.00
$ 216.00
$ 216.00 - $ 216.00
$ 216.00
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 %
$ 312.00
$ 312.00 - $ 312.00
$ 312.00
$ 250.00
$ 250.00 - $ 250.00
$ 250.00

Foster 3203H, 1/4" Industrial Coupler x 3/8" Female NPT, 3 Series, Heat/Viton, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3203H is a Steel 1/4" industrial coupler from the Foster 3 Series — the mo...

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$ 312.00
$ 312.00 - $ 312.00
$ 312.00
$ 250.00
$ 250.00 - $ 250.00
$ 250.00
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 %
$ 325.00
$ 325.00 - $ 325.00
$ 325.00
$ 259.00
$ 259.00 - $ 259.00
$ 259.00

Foster BL3203, 1/4" Industrial Coupler x 3/8" Female NPT, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL3203 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series —...

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$ 325.00
$ 325.00 - $ 325.00
$ 325.00
$ 259.00
$ 259.00 - $ 259.00
$ 259.00
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 %
$ 287.00
$ 287.00 - $ 287.00
$ 287.00
$ 231.00
$ 231.00 - $ 231.00
$ 231.00

Foster 3203, 1/4" Industrial Coupler x 3/8" Female NPT, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3203 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — t...

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$ 287.00
$ 287.00 - $ 287.00
$ 287.00
$ 231.00
$ 231.00 - $ 231.00
$ 231.00
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 %
$ 442.00
$ 442.00 - $ 442.00
$ 442.00
$ 354.00
$ 354.00 - $ 354.00
$ 354.00

Foster BL3003W, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Ball Lock, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL3003W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — t...

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$ 442.00
$ 442.00 - $ 442.00
$ 442.00
$ 354.00
$ 354.00 - $ 354.00
$ 354.00
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 %
$ 363.00
$ 363.00 - $ 363.00
$ 363.00
$ 289.00
$ 289.00 - $ 289.00
$ 289.00

Foster 3003W, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3003W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — the...

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$ 363.00
$ 363.00 - $ 363.00
$ 363.00
$ 289.00
$ 289.00 - $ 289.00
$ 289.00
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 %
$ 896.00
$ 896.00 - $ 896.00
$ 896.00
$ 716.00
$ 716.00 - $ 716.00
$ 716.00

Foster 3003S/SH, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Heat/Viton, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3003S/SH is a 303 Stainless 1/4" industrial coupler from the Foster 3 Seri...

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$ 896.00
$ 896.00 - $ 896.00
$ 896.00
$ 716.00
$ 716.00 - $ 716.00
$ 716.00
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 %
$ 943.00
$ 943.00 - $ 943.00
$ 943.00
$ 754.00
$ 754.00 - $ 754.00
$ 754.00

Foster BL3003S/S, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Ball Lock, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL3003S/S is a 303 Stainless 1/4" industrial coupler from the Foster 3 Ser...

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$ 943.00
$ 943.00 - $ 943.00
$ 943.00
$ 754.00
$ 754.00 - $ 754.00
$ 754.00
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 %
$ 837.00
$ 837.00 - $ 837.00
$ 837.00
$ 669.00
$ 669.00 - $ 669.00
$ 669.00

Foster 3003S/S, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3003S/S is a 303 Stainless 1/4" industrial coupler from the Foster 3 Serie...

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$ 837.00
$ 837.00 - $ 837.00
$ 837.00
$ 669.00
$ 669.00 - $ 669.00
$ 669.00
Save 20% Save %

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