Dripper Guard prevents boat hull stains caused by boat thru-hulls. Designed of soft, flexible rubber, UV protected and 3M bonding; it’s perfect for any component on your boat that has a thru-hull. Ideal for preventing stains from air conditioner, sink, generator, shower, bilge pump, bait well, and sump pump thru-hulls. Forget the boat hull cleaner and make your boat maintenance a breeze with Dripper Guard.