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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 %
$ 537.00
$ 537.00 - $ 537.00
$ 537.00
$ 429.00
$ 429.00 - $ 429.00
$ 429.00

Foster 3653GB, 1/4" Industrial Coupler x 5/16" Hose ID, 3 Series, Automatic Slim Profile, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3653GB is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 537.00
$ 537.00 - $ 537.00
$ 537.00
$ 429.00
$ 429.00 - $ 429.00
$ 429.00
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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 %
$ 428.00
$ 428.00 - $ 428.00
$ 428.00
$ 343.00
$ 343.00 - $ 343.00
$ 343.00

Foster 3603GS, 1/4" Industrial Coupler x 1/4" Hose ID, 3 Series, Automatic Slim Profile, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3603GS is a Steel 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 428.00
$ 428.00 - $ 428.00
$ 428.00
$ 343.00
$ 343.00 - $ 343.00
$ 343.00
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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 %
$ 545.00
$ 545.00 - $ 545.00
$ 545.00
$ 437.00
$ 437.00 - $ 437.00
$ 437.00

Foster 3603GB, 1/4" Industrial Coupler x 1/4" Hose ID, 3 Series, Automatic Slim Profile, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3603GB is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 545.00
$ 545.00 - $ 545.00
$ 545.00
$ 437.00
$ 437.00 - $ 437.00
$ 437.00
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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 %
$ 422.00
$ 422.00 - $ 422.00
$ 422.00
$ 337.00
$ 337.00 - $ 337.00
$ 337.00

Foster 3303GS, 1/4" Industrial Coupler x 3/8" Male NPT, 3 Series, Automatic Slim Profile, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3303GS is a Steel 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 422.00
$ 422.00 - $ 422.00
$ 422.00
$ 337.00
$ 337.00 - $ 337.00
$ 337.00
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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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$ 533.00
$ 533.00 - $ 533.00
$ 533.00
$ 426.00
$ 426.00 - $ 426.00
$ 426.00

Foster 3303GB, 1/4" Industrial Coupler x 3/8" Male NPT, 3 Series, Automatic Slim Profile, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3303GB is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 533.00
$ 533.00 - $ 533.00
$ 533.00
$ 426.00
$ 426.00 - $ 426.00
$ 426.00
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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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$ 409.00
$ 409.00 - $ 409.00
$ 409.00
$ 327.00
$ 327.00 - $ 327.00
$ 327.00

Foster 3103GS, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Automatic Slim Profile, Steel

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

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$ 409.00
$ 409.00 - $ 409.00
$ 409.00
$ 327.00
$ 327.00 - $ 327.00
$ 327.00
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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 %
$ 505.00
$ 505.00 - $ 505.00
$ 505.00
$ 405.00
$ 405.00 - $ 405.00
$ 405.00

Foster 3103GB, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Automatic Slim Profile, Brass

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

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$ 505.00
$ 505.00 - $ 505.00
$ 505.00
$ 405.00
$ 405.00 - $ 405.00
$ 405.00
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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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$ 498.00
$ 498.00 - $ 498.00
$ 498.00
$ 399.00
$ 399.00 - $ 399.00
$ 399.00

Foster 2903GS, 1/4" Industrial Coupler x 1/8" Male NPT, 3 Series, Automatic Slim Profile, Steel

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

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$ 498.00
$ 498.00 - $ 498.00
$ 498.00
$ 399.00
$ 399.00 - $ 399.00
$ 399.00
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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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$ 698.00
$ 698.00 - $ 698.00
$ 698.00
$ 558.00
$ 558.00 - $ 558.00
$ 558.00

Foster 2903GB, 1/4" Industrial Coupler x 1/8" Male NPT, 3 Series, Automatic Slim Profile, Brass

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

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$ 698.00
$ 698.00 - $ 698.00
$ 698.00
$ 558.00
$ 558.00 - $ 558.00
$ 558.00
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 %
$ 428.00
$ 428.00 - $ 428.00
$ 428.00
$ 343.00
$ 343.00 - $ 343.00
$ 343.00

Foster 3203GS, 1/4" Industrial Coupler x 3/8" Female NPT, 3 Series, Automatic Slim Profile, Steel

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

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$ 428.00
$ 428.00 - $ 428.00
$ 428.00
$ 343.00
$ 343.00 - $ 343.00
$ 343.00
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 %
$ 552.00
$ 552.00 - $ 552.00
$ 552.00
$ 443.00
$ 443.00 - $ 443.00
$ 443.00

Foster 3203GB, 1/4" Industrial Coupler x 3/8" Female NPT, 3 Series, Automatic Slim Profile, Brass

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

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$ 552.00
$ 552.00 - $ 552.00
$ 552.00
$ 443.00
$ 443.00 - $ 443.00
$ 443.00
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
$ 325.00
$ 325.00 - $ 325.00
$ 325.00

Foster 3003GS, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Automatic Slim Profile, Steel

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

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$ 407.00
$ 407.00 - $ 407.00
$ 407.00
$ 325.00
$ 325.00 - $ 325.00
$ 325.00
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 %
$ 445.00
$ 445.00 - $ 445.00
$ 445.00
$ 356.00
$ 356.00 - $ 356.00
$ 356.00

Foster 3003GB, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Automatic Slim Profile, Brass

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

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$ 445.00
$ 445.00 - $ 445.00
$ 445.00
$ 356.00
$ 356.00 - $ 356.00
$ 356.00
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 %
$ 562.00
$ 562.00 - $ 562.00
$ 562.00
$ 450.00
$ 450.00 - $ 450.00
$ 450.00

Foster 2803GS, 1/4" Industrial Coupler x 1/8" Female NPT, 3 Series, Automatic Slim Profile, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 2803GS is a Steel 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 562.00
$ 562.00 - $ 562.00
$ 562.00
$ 450.00
$ 450.00 - $ 450.00
$ 450.00
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 %
$ 486.00
$ 486.00 - $ 486.00
$ 486.00
$ 388.00
$ 388.00 - $ 388.00
$ 388.00

Foster 2803GB, 1/4" Industrial Coupler x 1/8" Female NPT, 3 Series, Automatic Slim Profile, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 2803GB is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 486.00
$ 486.00 - $ 486.00
$ 486.00
$ 388.00
$ 388.00 - $ 388.00
$ 388.00
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 %
$ 653.00
$ 653.00 - $ 653.00
$ 653.00
$ 522.00
$ 522.00 - $ 522.00
$ 522.00

Foster SLSD13-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 13/16" OD, 3 Series, Automatic Sleeve Lock, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SLSD13-3 is a Brass 1/4" industrial coupler from the Foster 3 Series — the...

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$ 653.00
$ 653.00 - $ 653.00
$ 653.00
$ 522.00
$ 522.00 - $ 522.00
$ 522.00
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 %
$ 620.00
$ 620.00 - $ 620.00
$ 620.00
$ 496.00
$ 496.00 - $ 496.00
$ 496.00

Foster SLSD11-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 3/4" OD, 3 Series, Automatic Sleeve Lock, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SLSD11-3 is a Brass 1/4" industrial coupler from the Foster 3 Series — the...

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$ 620.00
$ 620.00 - $ 620.00
$ 620.00
$ 496.00
$ 496.00 - $ 496.00
$ 496.00
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 %
$ 609.00
$ 609.00 - $ 609.00
$ 609.00
$ 488.00
$ 488.00 - $ 488.00
$ 488.00

Foster SLSD9-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 11/16" OD, 3 Series, Automatic Sleeve Lock, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SLSD9-3 is a Brass 1/4" industrial coupler from the Foster 3 Series — the ...

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$ 609.00
$ 609.00 - $ 609.00
$ 609.00
$ 488.00
$ 488.00 - $ 488.00
$ 488.00
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 %
$ 602.00
$ 602.00 - $ 602.00
$ 602.00
$ 481.00
$ 481.00 - $ 481.00
$ 481.00

Foster SLSD7-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 5/8" OD, 3 Series, Automatic Sleeve Lock, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SLSD7-3 is a Brass 1/4" industrial coupler from the Foster 3 Series — the ...

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$ 602.00
$ 602.00 - $ 602.00
$ 602.00
$ 481.00
$ 481.00 - $ 481.00
$ 481.00
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 %
$ 828.00
$ 828.00 - $ 828.00
$ 828.00
$ 664.00
$ 664.00 - $ 664.00
$ 664.00

Foster SLSC7-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 5/16" ID x 5/8" OD, 3 Series, Automatic Sleeve Lock, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SLSC7-3 is a Brass 1/4" industrial coupler from the Foster 3 Series — the ...

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$ 828.00
$ 828.00 - $ 828.00
$ 828.00
$ 664.00
$ 664.00 - $ 664.00
$ 664.00
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 %
$ 828.00
$ 828.00 - $ 828.00
$ 828.00
$ 664.00
$ 664.00 - $ 664.00
$ 664.00

Foster SLSC5-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 5/16" ID x 9/16" OD, 3 Series, Automatic Sleeve Lock, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SLSC5-3 is a Brass 1/4" industrial coupler from the Foster 3 Series — the ...

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$ 828.00
$ 828.00 - $ 828.00
$ 828.00
$ 664.00
$ 664.00 - $ 664.00
$ 664.00
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 %
$ 628.00
$ 628.00 - $ 628.00
$ 628.00
$ 503.00
$ 503.00 - $ 503.00
$ 503.00

Foster SLSB7-3W, 1/4" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 5/8" OD, 3 Series, Automatic Sleeve Lock, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SLSB7-3W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — ...

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$ 628.00
$ 628.00 - $ 628.00
$ 628.00
$ 503.00
$ 503.00 - $ 503.00
$ 503.00
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 %
$ 566.00
$ 566.00 - $ 566.00
$ 566.00
$ 454.00
$ 454.00 - $ 454.00
$ 454.00

Foster SLSB7-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 5/8" OD, 3 Series, Automatic Sleeve Lock, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SLSB7-3 is a Brass 1/4" industrial coupler from the Foster 3 Series — the ...

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$ 566.00
$ 566.00 - $ 566.00
$ 566.00
$ 454.00
$ 454.00 - $ 454.00
$ 454.00
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 %
$ 585.00
$ 585.00 - $ 585.00
$ 585.00
$ 467.00
$ 467.00 - $ 467.00
$ 467.00

Foster SLSB5-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 9/16" OD, 3 Series, Automatic Sleeve Lock, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SLSB5-3 is a Brass 1/4" industrial coupler from the Foster 3 Series — the ...

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$ 585.00
$ 585.00 - $ 585.00
$ 585.00
$ 467.00
$ 467.00 - $ 467.00
$ 467.00
Save 20% Save %

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