The Middle Atlantic RC-4 clamping rack shelf features rubber-lined clamps that secure your component from the top. It is additionally outfitted with adjustable L brackets in back to provide an optimally secure fit. Vented bottoms offer superior cooling, while a robust 16-gauge steel design maintains structural integrity, even on the road. Racking height: 7″ (4 space) Usable shelf area: 17.38″W x 15.10″D Clamping height range: 4-5/8″ to 6-3/8″ Weight capacity: 85 lbs