At BikeMaster, they understand the quality and performance that motorcycle owners demand. They also understand that quality should be affordable. Not just for professional riders and mechanics, but for the everyday rider / mechanic as well. That is why BikeMaster continues to bring that level of quality and performance to all riders with their complete line of tools, parts and accessories at affordable prices. Protects the exhaust system from water during pressure washing. Keeps humidity from entering pipe as it cools down or prevents condensation inside the pipe during storage. Formulated to be stiff enough to not fall out but soft enough to insert into the pipe without damage. Sizing: Small: Minimum diameter of 14.75 mm / maximum diameter of 37.75 mm. Fits most 2-stroke applications. Large: Minimum diameter of 33 mm / maximum diameter of 61 mm.