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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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€7,95 - €7,95
€7,95
€7,95 - €7,95
€7,95

Foster 47-4, 4 Series, Industrial Plug, 5/16" Hose Barb, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 47-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-flo...

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€7,95 - €7,95
€7,95
€7,95 - €7,95
€7,95
€4,95 - €4,95
€4,95
€4,95 - €4,95
€4,95

Foster 71-4, 4 Series, Industrial Plug, 3/8" Push-On Hose Barb, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 71-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-flo...

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€4,95 - €4,95
€4,95
€4,95 - €4,95
€4,95
€5,95 - €5,95
€5,95
€5,95 - €5,95
€5,95

Foster 49-4, 4 Series, Industrial Plug, 1/2" Hose Barb, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 49-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-flo...

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€5,95 - €5,95
€5,95
€5,95 - €5,95
€5,95
€17,95 - €17,95
€17,95
€17,95 - €17,95
€17,95

Foster 4304, 4 Series, Industrial Coupler, Manual, 3/8" Male NPT, Brass, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 4304 is a Brass/Steel 3/8" industrial coupler from the Foster 4 Series — a...

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€17,95 - €17,95
€17,95
€17,95 - €17,95
€17,95
€22,95 - €22,95
€22,95
€22,95 - €22,95
€22,95

Foster FM4604, 4 Series, Industrial Coupler, Automatic, 1/4" Hose Barb, Brass

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster FM4604 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
€8,95 - €8,95
€8,95
€8,95 - €8,95
€8,95

Foster 38-4, 4 Series, Industrial Plug, 1/8" Male NPT, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 38-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-flo...

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€8,95 - €8,95
€8,95
€8,95 - €8,95
€8,95
€5,95 - €5,95
€5,95
€5,95 - €5,95
€5,95

Foster 51-4, 4 Series, Industrial Plug, 1/4" Push-On Hose Barb, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 51-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-flo...

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€5,95 - €5,95
€5,95
€5,95 - €5,95
€5,95
€19,95 - €19,95
€19,95
€19,95 - €19,95
€19,95

Foster 71-4B, 4 Series, Industrial Plug, 3/8" Push-On Hose Barb, Brass

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 71-4B is a Brass 3/8" industrial plug from the Foster 4 Series — a high-fl...

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€19,95 - €19,95
€19,95
€19,95 - €19,95
€19,95
€7,95 - €7,95
€7,95
€7,95 - €7,95
€7,95

Foster 81-4, 4 Series, Industrial Plug, 1/2" Push-On Hose Barb, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 81-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-flo...

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€7,95 - €7,95
€7,95
€7,95 - €7,95
€7,95
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 4604, 4 Series, Industrial Coupler, Manual, 1/4" Hose Barb, Brass, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 4604 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
€20,95 - €20,95
€20,95
€20,95 - €20,95
€20,95

Foster 4704, 4 Series, Industrial Coupler, Manual, 5/16" Hose Barb, Brass, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster 4704 is a Brass/Steel 3/8" industrial coupler from the Foster 4 Series — a...

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€20,95 - €20,95
€20,95
€20,95 - €20,95
€20,95
€20,95 - €20,95
€20,95
€20,95 - €20,95
€20,95

Foster 4804, 4 Series, Industrial Coupler, Manual, 3/8" Hose Barb, Brass, Steel

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

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€20,95 - €20,95
€20,95
€20,95 - €20,95
€20,95
€19,95 - €19,95
€19,95
€19,95 - €19,95
€19,95

Foster 4904, 4 Series, Industrial Coupler, Manual, 1/2" Hose Barb, 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...

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€19,95 - €19,95
€19,95
€19,95 - €19,95
€19,95
€17,95 - €17,95
€17,95
€17,95 - €17,95
€17,95

Foster 1714, 4 Series, Industrial Coupler, Manual, 3/8" Hose Barb (Push-On), 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...

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€17,95 - €17,95
€17,95
€17,95 - €17,95
€17,95
€19,95 - €19,95
€19,95
€19,95 - €19,95
€19,95

Foster 1814, 4 Series, Industrial Coupler, Manual, 1/2" Hose Barb (Push-On), 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
€23,95 - €23,95
€23,95
€23,95 - €23,95
€23,95

Foster FM4704, 4 Series, Industrial Coupler, Automatic, 5/16" Hose Barb, Brass

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster FM4704 is a Brass 3/8" industrial coupler from the Foster 4 Series — a hig...

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€23,95 - €23,95
€23,95
€23,95 - €23,95
€23,95
€25,95 - €25,95
€25,95
€25,95 - €25,95
€25,95

Foster FM1814, 4 Series, Industrial Coupler, Manual, 1/2" Hose Barb (Push-On), Brass

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster FM1814 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
€14,95 - €14,95
€14,95
€14,95 - €14,95
€14,95

Foster PD13-4, 3/8" Industrial Plug x Reusable Hose Fitting, 3/8" ID x 13/16" OD, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster PD13-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-f...

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€14,95 - €14,95
€14,95
€14,95 - €14,95
€14,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€11,95 - €11,95
€11,95
€11,95 - €11,95
€11,95

Foster PD11-4, 3/8" Industrial Plug x Reusable Hose Fitting, 3/8" ID x 3/4" OD, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster PD11-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-f...

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€11,95 - €11,95
€11,95
€11,95 - €11,95
€11,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€10,95 - €10,95
€10,95
€10,95 - €10,95
€10,95

Foster PD9-4, 3/8" Industrial Plug x Reusable Hose Fitting, 3/8" ID x 11/16" OD, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster PD9-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-fl...

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€10,95 - €10,95
€10,95
€10,95 - €10,95
€10,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€10,95 - €10,95
€10,95
€10,95 - €10,95
€10,95

Foster PD7-4, 3/8" Industrial Plug x Reusable Hose Fitting, 3/8" ID x 5/8" OD, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster PD7-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-fl...

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€10,95 - €10,95
€10,95
€10,95 - €10,95
€10,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€11,95 - €11,95
€11,95
€11,95 - €11,95
€11,95

Foster PB7-4, 3/8" Industrial Plug x Reusable Hose Fitting, 1/4" ID x 5/8" OD, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster PB7-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-fl...

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€11,95 - €11,95
€11,95
€11,95 - €11,95
€11,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€9,95 - €9,95
€9,95
€9,95 - €9,95
€9,95

Foster PB5-4, 3/8" Industrial Plug x Reusable Hose Fitting, 1/4" ID x 9/16" OD, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster PB5-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-fl...

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€9,95 - €9,95
€9,95
€9,95 - €9,95
€9,95
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
€10,95 - €10,95
€10,95
€10,95 - €10,95
€10,95

Foster PB3-4, 3/8" Industrial Plug x Reusable Hose Fitting, 1/4" ID x 1/2" OD, 4 Series, Steel

Reliable, leak-free 3/8" connections for air and fluid lines. The Foster PB3-4 is a Steel 3/8" industrial plug from the Foster 4 Series — a high-fl...

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€10,95 - €10,95
€10,95
€10,95 - €10,95
€10,95

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