3 Meter Silicone Hose Kit Set For Engine Bay Dress Up 4Mm 6Mm 8Mm 12Mm Purple P3 for Ford F-350 Super Duty This is a set of four (4) 3 meter sections of hose. Inner diameter for first hose is 4MM (3/20"). Outer diameter is 8MM (8/25"). Inner diameter for second hose is 6MM (1/4"). Outer diameter is 10MM (2/5).