When replacing your liner, you should replace any previous step gasket material. The Aqua Select Step Gasket is a white Neoprene material that will ensure a watertight seal around your fiberglass steps to prevent possible leaking from behind the liner. Our product is sold without holes and can be universally used. The 20' roll of gasket material can cover 4' x 8' steps. Roll measures: 1 1/4" wide x 1/8" thick. Step gasket material should be replaced when changing your liner.