The quality of materials CV4 uses allows the inner diameter of the hoses to be much smoother then O.E.M. which increases fluid flow allowing for higher performance. Polyester reinforced silicone that provides better flow and durability then O.E.M. radiator hoses. Designed for vent lines on carburetors, gas cap overflow, radiator overflow, water pump bypass, oil cooler and various other applications. Working operating temperature up to 420°F. Note: NOT designed for continuous exposure to fuel.