Camco's Clear RV Sewer Cap with Lanyard helps prevent leaks and spills from your RV's sewer system. It is compatible with 3 In. RV waste valves and is clear to allow you to see what's behind the cap, so you anticipate what's there. A bayonet fitting creates a secure connection with four points of attachment. Made of heavy-duty plastic with UV inhibitors for years of use. Includes a lanyard to help prevent loss.