West Marines Nylon Vent Plugs are ideal for venting areas that may be subjected to heat or moisture build-up. Small and packaged conveniently with 4 plugs, our Nylon Vent Plugs are easy to install. Whether placed in a designated vent hole or used to plug holes where old lights have been removed, vents help keep your boat or anchor lock room fresh and mildew-free. Specifications Inner Diameter: 1" Outside Diameter: 1 1/4" Diameter: 1/4" Quantity: 4