Camco Brass Blow-out Plug Completely clear your water lines with the Camco Brass Blow-out Plug. Use this plug for winterizing to prevent your water lines from freezing. Using a blow-out pump to clear your water lines will help extend the life of your water heater. For use with 1 diameter drains. Instructions Screw the blow-out plug into the city water inlet Open all drains and faucets Attach and activate air pump until all lines are clear California Residents WARNING Cancer and Reproductive Harm