Made from tough climate tested rubber Spring-loaded double check valves Stainless steel hose clamps Speed Prime technology Fits both 5/16″ and 3/8″ fuel lines.Rugged, tough and reliable, Invincible Marine offers top of the line boating products and marine accessories at affordable prices, and is well-known for their hardworking nautical line. For freshwater and saltwater boating, Invincible Marine designs products for avid fishermen and weekend boaters. Quality, utility and innovation go into every Invincible Marine product giving you more time on the water.