1. Installed in 1" (25.4mm) drain hole, When locking, the durable gasket can ensure no leakage during movement, suitable for boat transom, livewell, ice chest cooler, etc. 2. The 316 grade stainless steel and the perfect polished surface are both aesthetically pleasing and durable, even in saltwater environments. 3. Larger and smoother design on the plug's head helps to turn and take it out or lock it tight. 4. No-drop design, the plug can be fixed on the base, you can take the plug out at any time and do not need to worry about it will be lost. 5. Pack for 1 pieces drain plugs,