Read the wall requirement first: the supplied hanging kits are rated for concrete and brick, not for hollow drywall on its own. Given a masonry wall, the unit gives back the whole floor beneath a 41.5-in by 21-in surface, with three cubes built into the body rather than bolted on afterward. The middle bay measures 18 in wide and the two flanking cubes 10.5 in each, all 5.5 in deep for books, a router, or folded cables. Loading is modest by design at 45 lb across the top and 35 lb per cube, matching a laptop rather than a tower and dual screens.