Manufactured to be used with Earl's new Ultra-Flex 650™ hose, Earl's QD hose ends are made to reduce time, space and weight issues in certain racing situations. These hose ends are threadless and the male and female designs are manufactured for smooth and effortless installations every time. They are coupled by a threadless clamshell closure (sold separately) that is manufactured by the leader in the industry - Adel Wiggins.