Eliminates loss of transmission fluid and messy, slippery floors. Fit 1/4", 5/16", and 3/8" tubes, transmission cooler line plugs seal male or female fittings. 16" chain keeps plugs together and serves as a tube support. Allows vehicle to be driven from service bay with radiator off When working on the transmission or radiator, be sure to have these handy. The plug seals male or female fittings just like faucet valve. You don't have to worry about transmission fluid leaking out everywhere. Works great, and are easy to install.