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Foster 4 Series Couplers

The Foster 4 Series is the 3/8" body industrial interchange, one of the most common air coupler sizes for shop and industrial use. This collection includes 4 Series couplers and plugs in brass, steel, and stainless with NPT, hose barb, push-on, and reusable terminations. 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
€26,95 - €26,95
€26,95
€26,95 - €26,95
€26,95

Foster SL4204, 3/8" Industrial Coupler x 3/8" Female NPT, 4 Series, Automatic Sleeve Lock, Brass

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster SL4204 is a Brass 3/8" industrial coupler from the Foster 4 Series — a hig...

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€26,95 - €26,95
€26,95
€26,95 - €26,95
€26,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€22,95 - €22,95
€22,95
€22,95 - €22,95
€22,95

Foster FM4204, 3/8" Industrial Coupler x 3/8" Female NPT, 4 Series, Automatic, Brass

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster FM4204 is a Brass 3/8" industrial coupler from the Foster 4 Series — a hig...

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€22,95 - €22,95
€22,95
€22,95 - €22,95
€22,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€25,95 - €25,95
€25,95
€25,95 - €25,95
€25,95

Foster SL4004, 3/8" Industrial Coupler x 1/4" Female NPT, 4 Series, Automatic Sleeve Lock, Brass

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster SL4004 is a Brass 3/8" industrial coupler from the Foster 4 Series — a hig...

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€25,95 - €25,95
€25,95
€25,95 - €25,95
€25,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€22,95 - €22,95
€22,95
€22,95 - €22,95
€22,95

Foster FM4004, 3/8" Industrial Coupler x 1/4" Female NPT, 4 Series, Automatic, Brass

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster FM4004 is a Brass 3/8" industrial coupler from the Foster 4 Series — a hig...

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€22,95 - €22,95
€22,95
€22,95 - €22,95
€22,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€23,95 - €23,95
€23,95
€23,95 - €23,95
€23,95

Foster SD13-4, 3/8" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 13/16" OD, 4 Series, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster SD13-4 is a Brass/Steel 3/8" industrial coupler from the Foster 4 Series —...

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€23,95 - €23,95
€23,95
€23,95 - €23,95
€23,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€22,95 - €22,95
€22,95
€22,95 - €22,95
€22,95

Foster SD11-4, 3/8" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 3/4" OD, 4 Series, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster SD11-4 is a Brass/Steel 3/8" industrial coupler from the Foster 4 Series —...

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€22,95 - €22,95
€22,95
€22,95 - €22,95
€22,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€25,95 - €25,95
€25,95
€25,95 - €25,95
€25,95

Foster BLSD9-4, 3/8" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 11/16" OD, 4 Series, Ball Lock, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster BLSD9-4 is a Brass/Steel 3/8" industrial coupler from the Foster 4 Series ...

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€25,95 - €25,95
€25,95
€25,95 - €25,95
€25,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€21,95 - €21,95
€21,95
€21,95 - €21,95
€21,95

Foster SD9-4, 3/8" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 11/16" OD, 4 Series, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster SD9-4 is a Brass/Steel 3/8" industrial coupler from the Foster 4 Series — ...

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€21,95 - €21,95
€21,95
€21,95 - €21,95
€21,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€25,95 - €25,95
€25,95
€25,95 - €25,95
€25,95

Foster BLSD7-4, 3/8" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 5/8" OD, 4 Series, Ball Lock, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster BLSD7-4 is a Brass/Steel 3/8" industrial coupler from the Foster 4 Series ...

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€25,95 - €25,95
€25,95
€25,95 - €25,95
€25,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€21,95 - €21,95
€21,95
€21,95 - €21,95
€21,95

Foster SD7-4, 3/8" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 5/8" OD, 4 Series, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster SD7-4 is a Brass/Steel 3/8" industrial coupler from the Foster 4 Series — ...

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€21,95 - €21,95
€21,95
€21,95 - €21,95
€21,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€24,95 - €24,95
€24,95
€24,95 - €24,95
€24,95

Foster SB7-4, 3/8" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 5/8" OD, 4 Series, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster SB7-4 is a Brass/Steel 3/8" industrial coupler from the Foster 4 Series — ...

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€24,95 - €24,95
€24,95
€24,95 - €24,95
€24,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€25,95 - €25,95
€25,95
€25,95 - €25,95
€25,95

Foster SB5-4, 3/8" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 9/16" OD, 4 Series, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster SB5-4 is a Brass/Steel 3/8" industrial coupler from the Foster 4 Series — ...

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€25,95 - €25,95
€25,95
€25,95 - €25,95
€25,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€24,95 - €24,95
€24,95
€24,95 - €24,95
€24,95

Foster SB3-4, 3/8" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 1/2" OD, 4 Series, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster SB3-4 is a Brass/Steel 3/8" industrial coupler from the Foster 4 Series — ...

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€24,95 - €24,95
€24,95
€24,95 - €24,95
€24,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€24,95 - €24,95
€24,95
€24,95 - €24,95
€24,95

Foster 1814W, 3/8" Industrial Coupler x 1/2" Push-On Hose Stem, 4 Series, Water, Brass/SS

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 1814W is a Brass/SS 3/8" industrial coupler from the Foster 4 Series — a h...

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€24,95 - €24,95
€24,95
€24,95 - €24,95
€24,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€20,95 - €20,95
€20,95
€20,95 - €20,95
€20,95

Foster BL1814, 3/8" Industrial Coupler x 1/2" Push-On Hose Stem, 4 Series, Ball Lock, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster BL1814 is a Brass/Steel 3/8" industrial coupler from the Foster 4 Series —...

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€20,95 - €20,95
€20,95
€20,95 - €20,95
€20,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€19,95 - €19,95
€19,95
€19,95 - €19,95
€19,95

Foster 1814, 3/8" Industrial Coupler x 1/2" Push-On Hose Stem, 4 Series, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 1814 is a Brass/Steel 3/8" industrial coupler from the Foster 4 Series — a...

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€19,95 - €19,95
€19,95
€19,95 - €19,95
€19,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€23,95 - €23,95
€23,95
€23,95 - €23,95
€23,95

Foster 1714W, 3/8" Industrial Coupler x 3/8" Push-On Hose Stem, 4 Series, Water, Brass/SS

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 1714W is a Brass/SS 3/8" industrial coupler from the Foster 4 Series — a h...

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€23,95 - €23,95
€23,95
€23,95 - €23,95
€23,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€19,95 - €19,95
€19,95
€19,95 - €19,95
€19,95

Foster BL1714, 3/8" Industrial Coupler x 3/8" Push-On Hose Stem, 4 Series, Ball Lock, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster BL1714 is a Brass/Steel 3/8" industrial coupler from the Foster 4 Series —...

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€19,95 - €19,95
€19,95
€19,95 - €19,95
€19,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€17,95 - €17,95
€17,95
€17,95 - €17,95
€17,95

Foster 1714, 3/8" Industrial Coupler x 3/8" Push-On Hose Stem, 4 Series, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 1714 is a Brass/Steel 3/8" industrial coupler from the Foster 4 Series — a...

View full details
€17,95 - €17,95
€17,95
€17,95 - €17,95
€17,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€23,95 - €23,95
€23,95
€23,95 - €23,95
€23,95

Foster 4904S, 3/8" Industrial Coupler x 1/2" Hose ID, 4 Series, Steam/EPDM, Brass body, Brass sleeve, SS valve

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 4904S is a Brass body, Brass sleeve, SS valve 3/8" industrial coupler from...

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€23,95 - €23,95
€23,95
€23,95 - €23,95
€23,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€24,95 - €24,95
€24,95
€24,95 - €24,95
€24,95

Foster BL4904, 3/8" Industrial Coupler x 1/2" Hose ID, 4 Series, Ball Lock, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster BL4904 is a Brass/Steel 3/8" industrial coupler from the Foster 4 Series —...

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€24,95 - €24,95
€24,95
€24,95 - €24,95
€24,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€19,95 - €19,95
€19,95
€19,95 - €19,95
€19,95

Foster 4904, 3/8" Industrial Coupler x 1/2" Hose ID, 4 Series, Brass/Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 4904 is a Brass/Steel 3/8" industrial coupler from the Foster 4 Series — a...

View full details
€19,95 - €19,95
€19,95
€19,95 - €19,95
€19,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€23,95 - €23,95
€23,95
€23,95 - €23,95
€23,95

Foster 4804W, 3/8" Industrial Coupler x 3/8" Hose ID, 4 Series, Water, Brass/SS

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 4804W is a Brass/SS 3/8" industrial coupler from the Foster 4 Series — a h...

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€23,95 - €23,95
€23,95
€23,95 - €23,95
€23,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€24,95 - €24,95
€24,95
€24,95 - €24,95
€24,95

Foster 4804S, 3/8" Industrial Coupler x 3/8" Hose ID, 4 Series, Steam/EPDM, Brass body, Brass sleeve, SS valve

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 4804S is a Brass body, Brass sleeve, SS valve 3/8" industrial coupler from...

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€24,95 - €24,95
€24,95
€24,95 - €24,95
€24,95

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