The Avenue 2-Piece Combo is comprised of a flat box, or manny pad, with a hubba on one end of it. The surface of the ledge and hubba are both marble and the base of it is wooden. This gives the obstacle a nice weight so it won't slide around, but won't be super heavy and inconvenient to reposition. The granite surface will give a nice, smooth feel when riding it and make grinds feel super satisfying.