The Whitecap Compression Handle is designed to reduce and eliminate noise and rattle from hatches while the boat is underway. The handle uses a compressed gasket to create a watertight seal for compartments or hatches. Outer Diameter: 3"Cutout: 2-1/2"Surface Depth: 1/8" - 3/4"Shaft Length: 3/8"For Freshwater Installation Only Made of black nylon & chrome-plated zinc | Whitecap 3" Non-Locking Compression Handle, Chrome-Plated Zamac/Black Nylon