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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 %
$ 265.00
$ 265.00 - $ 265.00
$ 265.00
$ 213.00
$ 213.00 - $ 213.00
$ 213.00

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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$ 265.00
$ 265.00 - $ 265.00
$ 265.00
$ 213.00
$ 213.00 - $ 213.00
$ 213.00
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 %
$ 244.00
$ 244.00 - $ 244.00
$ 244.00
$ 195.00
$ 195.00 - $ 195.00
$ 195.00

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

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3103D 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 %
$ 277.00
$ 277.00 - $ 277.00
$ 277.00
$ 221.00
$ 221.00 - $ 221.00
$ 221.00

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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$ 277.00
$ 277.00 - $ 277.00
$ 277.00
$ 221.00
$ 221.00 - $ 221.00
$ 221.00
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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 %
$ 237.00
$ 237.00 - $ 237.00
$ 237.00
$ 190.00
$ 190.00 - $ 190.00
$ 190.00

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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$ 237.00
$ 237.00 - $ 237.00
$ 237.00
$ 190.00
$ 190.00 - $ 190.00
$ 190.00
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Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 1,343.00
$ 1,343.00 - $ 1,343.00
$ 1,343.00
$ 1,074.00
$ 1,074.00 - $ 1,074.00
$ 1,074.00

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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$ 1,343.00
$ 1,343.00 - $ 1,343.00
$ 1,343.00
$ 1,074.00
$ 1,074.00 - $ 1,074.00
$ 1,074.00
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 %
$ 1,258.00
$ 1,258.00 - $ 1,258.00
$ 1,258.00
$ 1,006.00
$ 1,006.00 - $ 1,006.00
$ 1,006.00

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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$ 1,258.00
$ 1,258.00 - $ 1,258.00
$ 1,258.00
$ 1,006.00
$ 1,006.00 - $ 1,006.00
$ 1,006.00
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 %
$ 345.00
$ 345.00 - $ 345.00
$ 345.00
$ 275.00
$ 275.00 - $ 275.00
$ 275.00

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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$ 345.00
$ 345.00 - $ 345.00
$ 345.00
$ 275.00
$ 275.00 - $ 275.00
$ 275.00
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 %
$ 322.00
$ 322.00 - $ 322.00
$ 322.00
$ 258.00
$ 258.00 - $ 258.00
$ 258.00

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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$ 322.00
$ 322.00 - $ 322.00
$ 322.00
$ 258.00
$ 258.00 - $ 258.00
$ 258.00
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
$ 249.00
$ 249.00 - $ 249.00
$ 249.00

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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$ 312.00
$ 312.00 - $ 312.00
$ 312.00
$ 249.00
$ 249.00 - $ 249.00
$ 249.00
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 %
$ 286.00
$ 286.00 - $ 286.00
$ 286.00
$ 230.00
$ 230.00 - $ 230.00
$ 230.00

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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$ 286.00
$ 286.00 - $ 286.00
$ 286.00
$ 230.00
$ 230.00 - $ 230.00
$ 230.00
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 %
$ 331.00
$ 331.00 - $ 331.00
$ 331.00
$ 265.00
$ 265.00 - $ 265.00
$ 265.00

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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$ 331.00
$ 331.00 - $ 331.00
$ 331.00
$ 265.00
$ 265.00 - $ 265.00
$ 265.00
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 %
$ 1,176.00
$ 1,176.00 - $ 1,176.00
$ 1,176.00
$ 941.00
$ 941.00 - $ 941.00
$ 941.00

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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$ 1,176.00
$ 1,176.00 - $ 1,176.00
$ 1,176.00
$ 941.00
$ 941.00 - $ 941.00
$ 941.00
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 %
$ 1,258.00
$ 1,258.00 - $ 1,258.00
$ 1,258.00
$ 1,006.00
$ 1,006.00 - $ 1,006.00
$ 1,006.00

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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$ 1,258.00
$ 1,258.00 - $ 1,258.00
$ 1,258.00
$ 1,006.00
$ 1,006.00 - $ 1,006.00
$ 1,006.00
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 %
$ 1,155.00
$ 1,155.00 - $ 1,155.00
$ 1,155.00
$ 924.00
$ 924.00 - $ 924.00
$ 924.00

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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$ 1,155.00
$ 1,155.00 - $ 1,155.00
$ 1,155.00
$ 924.00
$ 924.00 - $ 924.00
$ 924.00
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 %
$ 247.00
$ 247.00 - $ 247.00
$ 247.00
$ 199.00
$ 199.00 - $ 199.00
$ 199.00

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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$ 247.00
$ 247.00 - $ 247.00
$ 247.00
$ 199.00
$ 199.00 - $ 199.00
$ 199.00
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 %
$ 287.00
$ 287.00 - $ 287.00
$ 287.00
$ 230.00
$ 230.00 - $ 230.00
$ 230.00

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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$ 287.00
$ 287.00 - $ 287.00
$ 287.00
$ 230.00
$ 230.00 - $ 230.00
$ 230.00
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 %
$ 300.00
$ 300.00 - $ 300.00
$ 300.00
$ 239.00
$ 239.00 - $ 239.00
$ 239.00

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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$ 300.00
$ 300.00 - $ 300.00
$ 300.00
$ 239.00
$ 239.00 - $ 239.00
$ 239.00
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 %
$ 265.00
$ 265.00 - $ 265.00
$ 265.00
$ 213.00
$ 213.00 - $ 213.00
$ 213.00

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...

View full details
$ 265.00
$ 265.00 - $ 265.00
$ 265.00
$ 213.00
$ 213.00 - $ 213.00
$ 213.00
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 %
$ 407.00
$ 407.00 - $ 407.00
$ 407.00
$ 326.00
$ 326.00 - $ 326.00
$ 326.00

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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$ 407.00
$ 407.00 - $ 407.00
$ 407.00
$ 326.00
$ 326.00 - $ 326.00
$ 326.00
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 %
$ 334.00
$ 334.00 - $ 334.00
$ 334.00
$ 266.00
$ 266.00 - $ 266.00
$ 266.00

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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$ 334.00
$ 334.00 - $ 334.00
$ 334.00
$ 266.00
$ 266.00 - $ 266.00
$ 266.00
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 %
$ 825.00
$ 825.00 - $ 825.00
$ 825.00
$ 660.00
$ 660.00 - $ 660.00
$ 660.00

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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$ 825.00
$ 825.00 - $ 825.00
$ 825.00
$ 660.00
$ 660.00 - $ 660.00
$ 660.00
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 %
$ 868.00
$ 868.00 - $ 868.00
$ 868.00
$ 694.00
$ 694.00 - $ 694.00
$ 694.00

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...

View full details
$ 868.00
$ 868.00 - $ 868.00
$ 868.00
$ 694.00
$ 694.00 - $ 694.00
$ 694.00
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 %
$ 771.00
$ 771.00 - $ 771.00
$ 771.00
$ 616.00
$ 616.00 - $ 616.00
$ 616.00

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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$ 771.00
$ 771.00 - $ 771.00
$ 771.00
$ 616.00
$ 616.00 - $ 616.00
$ 616.00
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 %
$ 331.00
$ 331.00 - $ 331.00
$ 331.00
$ 265.00
$ 265.00 - $ 265.00
$ 265.00

Foster 3003S, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Steam/EPDM, Brass/SS

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

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$ 331.00
$ 331.00 - $ 331.00
$ 331.00
$ 265.00
$ 265.00 - $ 265.00
$ 265.00
Save 20% Save %

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