These cat stairs mount to a wall using a few screws into the wall studs. The steps are carpeted all around and doweled into the "stringer" that mounts to the wall. The steps are 8" deep and have a plywood core. The trim in the front of each step and the stringer are painted fiberboard. In this case, the customer requested the stairs so that the cats could access the top of a secretary where they like to sleep without having to claw their way up the side of the furniture. Custom design, delivery and installation are extra.