Converts a white Thetford-style waste valve (the 3" hook-style connection) to a standard 3" bayonet fitting, so you can run Valterra, Grentec, or Anonda-style sewer hoses and caps instead of hunting for Thetford-specific gear. Handy if your van's fitted with a Thetford valve but the rest of your hose kit uses the more common bayonet fittings; one adaptor sorts out the mismatch. Lightweight white plastic construction, built to sit right at the tank outlet without adding bulk.