Use this under your frame for a solid firm foundation when on a level surface. Our base plate has a hole at 2.5 inches to accept most types of scaffolding. Can be used in conjunction with a caster jack which allows maximum versatility. You can order the caster jack for use with casters or take the caster out and use the base plate to form a level jack for a stationary application. KAJ base plates come galvanized. Thickness of the plate is either 4mm or 8mm.