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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 %
$ 501.00
$ 501.00 - $ 501.00
$ 501.00
$ 402.00
$ 402.00 - $ 402.00
$ 402.00

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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$ 501.00
$ 501.00 - $ 501.00
$ 501.00
$ 402.00
$ 402.00 - $ 402.00
$ 402.00
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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 %
$ 388.00
$ 388.00 - $ 388.00
$ 388.00
$ 310.00
$ 310.00 - $ 310.00
$ 310.00

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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$ 388.00
$ 388.00 - $ 388.00
$ 388.00
$ 310.00
$ 310.00 - $ 310.00
$ 310.00
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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 %
$ 491.00
$ 491.00 - $ 491.00
$ 491.00
$ 392.00
$ 392.00 - $ 392.00
$ 392.00

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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$ 491.00
$ 491.00 - $ 491.00
$ 491.00
$ 392.00
$ 392.00 - $ 392.00
$ 392.00
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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 %
$ 376.00
$ 376.00 - $ 376.00
$ 376.00
$ 301.00
$ 301.00 - $ 301.00
$ 301.00

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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$ 376.00
$ 376.00 - $ 376.00
$ 376.00
$ 301.00
$ 301.00 - $ 301.00
$ 301.00
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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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$ 465.00
$ 465.00 - $ 465.00
$ 465.00
$ 372.00
$ 372.00 - $ 372.00
$ 372.00

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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$ 465.00
$ 465.00 - $ 465.00
$ 465.00
$ 372.00
$ 372.00 - $ 372.00
$ 372.00
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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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$ 458.00
$ 458.00 - $ 458.00
$ 458.00
$ 367.00
$ 367.00 - $ 367.00
$ 367.00

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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$ 458.00
$ 458.00 - $ 458.00
$ 458.00
$ 367.00
$ 367.00 - $ 367.00
$ 367.00
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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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$ 642.00
$ 642.00 - $ 642.00
$ 642.00
$ 513.00
$ 513.00 - $ 513.00
$ 513.00

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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$ 642.00
$ 642.00 - $ 642.00
$ 642.00
$ 513.00
$ 513.00 - $ 513.00
$ 513.00
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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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$ 393.00
$ 393.00 - $ 393.00
$ 393.00
$ 315.00
$ 315.00 - $ 315.00
$ 315.00

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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$ 393.00
$ 393.00 - $ 393.00
$ 393.00
$ 315.00
$ 315.00 - $ 315.00
$ 315.00
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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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$ 508.00
$ 508.00 - $ 508.00
$ 508.00
$ 407.00
$ 407.00 - $ 407.00
$ 407.00

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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$ 508.00
$ 508.00 - $ 508.00
$ 508.00
$ 407.00
$ 407.00 - $ 407.00
$ 407.00
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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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$ 374.00
$ 374.00 - $ 374.00
$ 374.00
$ 299.00
$ 299.00 - $ 299.00
$ 299.00

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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$ 374.00
$ 374.00 - $ 374.00
$ 374.00
$ 299.00
$ 299.00 - $ 299.00
$ 299.00
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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 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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$ 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 %
$ 517.00
$ 517.00 - $ 517.00
$ 517.00
$ 414.00
$ 414.00 - $ 414.00
$ 414.00

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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$ 517.00
$ 517.00 - $ 517.00
$ 517.00
$ 414.00
$ 414.00 - $ 414.00
$ 414.00
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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 %
$ 447.00
$ 447.00 - $ 447.00
$ 447.00
$ 357.00
$ 357.00 - $ 357.00
$ 357.00

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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$ 447.00
$ 447.00 - $ 447.00
$ 447.00
$ 357.00
$ 357.00 - $ 357.00
$ 357.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 600.00
$ 600.00 - $ 600.00
$ 600.00
$ 480.00
$ 480.00 - $ 480.00
$ 480.00

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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$ 600.00
$ 600.00 - $ 600.00
$ 600.00
$ 480.00
$ 480.00 - $ 480.00
$ 480.00
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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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$ 571.00
$ 571.00 - $ 571.00
$ 571.00
$ 456.00
$ 456.00 - $ 456.00
$ 456.00

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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$ 571.00
$ 571.00 - $ 571.00
$ 571.00
$ 456.00
$ 456.00 - $ 456.00
$ 456.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 560.00
$ 560.00 - $ 560.00
$ 560.00
$ 449.00
$ 449.00 - $ 449.00
$ 449.00

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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$ 560.00
$ 560.00 - $ 560.00
$ 560.00
$ 449.00
$ 449.00 - $ 449.00
$ 449.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 553.00
$ 553.00 - $ 553.00
$ 553.00
$ 442.00
$ 442.00 - $ 442.00
$ 442.00

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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$ 553.00
$ 553.00 - $ 553.00
$ 553.00
$ 442.00
$ 442.00 - $ 442.00
$ 442.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 762.00
$ 762.00 - $ 762.00
$ 762.00
$ 611.00
$ 611.00 - $ 611.00
$ 611.00

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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$ 762.00
$ 762.00 - $ 762.00
$ 762.00
$ 611.00
$ 611.00 - $ 611.00
$ 611.00
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 %
$ 762.00
$ 762.00 - $ 762.00
$ 762.00
$ 611.00
$ 611.00 - $ 611.00
$ 611.00

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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$ 762.00
$ 762.00 - $ 762.00
$ 762.00
$ 611.00
$ 611.00 - $ 611.00
$ 611.00
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 %
$ 578.00
$ 578.00 - $ 578.00
$ 578.00
$ 463.00
$ 463.00 - $ 463.00
$ 463.00

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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$ 578.00
$ 578.00 - $ 578.00
$ 578.00
$ 463.00
$ 463.00 - $ 463.00
$ 463.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 520.00
$ 520.00 - $ 520.00
$ 520.00
$ 418.00
$ 418.00 - $ 418.00
$ 418.00

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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$ 520.00
$ 520.00 - $ 520.00
$ 520.00
$ 418.00
$ 418.00 - $ 418.00
$ 418.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 538.00
$ 538.00 - $ 538.00
$ 538.00
$ 430.00
$ 430.00 - $ 430.00
$ 430.00

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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$ 538.00
$ 538.00 - $ 538.00
$ 538.00
$ 430.00
$ 430.00 - $ 430.00
$ 430.00
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 %
$ 527.00
$ 527.00 - $ 527.00
$ 527.00
$ 421.00
$ 421.00 - $ 421.00
$ 421.00

Foster SLSB3-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 1/2" OD, 3 Series, Automatic Sleeve Lock, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SLSB3-3 is a Brass 1/4" industrial coupler from the Foster 3 Series — the ...

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$ 527.00
$ 527.00 - $ 527.00
$ 527.00
$ 421.00
$ 421.00 - $ 421.00
$ 421.00
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 %
$ 538.00
$ 538.00 - $ 538.00
$ 538.00
$ 430.00
$ 430.00 - $ 430.00
$ 430.00

Foster FMSD13-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 13/16" OD, 3 Series, Automatic, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FMSD13-3 is a Brass 1/4" industrial coupler from the Foster 3 Series — the...

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$ 538.00
$ 538.00 - $ 538.00
$ 538.00
$ 430.00
$ 430.00 - $ 430.00
$ 430.00
Save 20% Save %

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