This listing is for a Pack of 1 A long thread white tap hole stopper (also known as a white tap hole blanking plug or blanking cap) is a white plastic plumbing cap used to cover and seal unused tap holes in sinks, basins, countertops, or baths. Sits flush on top of the sink or basin surface, providing a clean, color-matched aesthetic. Plastic Backnut screws onto the threaded tail from beneath the sink to clamp the stopper firmly in place. When replacing separate hot/cold pillartaps with a single mixer tap one tap hole is left open. The stopper blanks off the redundant hole.