After I purchased Woodwave's floating cabinets, I saw how the wall mounts work - very ingenious. There is a sort-of vertical cantilever mechanism that presses the cabinet into the wall. As long as you put a few felt protectors on your cabinet, or shelf, or speaker, it won't mar the wall but is held in place securely. I ordered additional holders to mount center and rear-surround speakers to the wall. They look great, highly recommenced.
