WS: welded wall shelfThe WS Series heavy duty, wall mount shelf is ideal for amplifiers and similar audio visual electronics where a full size rack may not be practical. The shelf is 21 in. wide with an overall depth of 17 in. One piece construction of 16 gauge welded steel makes this a sturdy addition to the system set up. Load capacity 200 lbs. [91 kg] when properly mounted Mounts easily using keyhole slots on 8 in. and 16 in. centers Made in the USA with certified U.