General description Made of high-quality 304 stainless steel and rubber, the CSPARKV Adjustable Marine Drain Plug is strong and durable. It is designed to be installed from the inside of the back plate, allowing for full adjustability without leaking or wobbling under vibration. This drain plug is suitable for 1 inch (25mm) holes, making it ideal for bottom tanks and stern plates of dam hulls. Technical specifications Material: 304 stainless steel and rubber Compatible hole size: 1 inch (25mm) Package includes 1 x Drain Plug