Middle Atlantic RC-3 Clamping Rack Shelf Clamping shelf rack has a rubber-lined clamp to hold components securely The Middle Atlantic RC-3 Clamping Rack Shelf is a universal 3-space rack mount for non-rackmountable gear 2 adjustable clamps hold items securely in place The Middle Atlantic RC-3 Clamping Rack Shelf is a universal 3-space rack mount for non-rackmountable gear 2 adjustable clamps hold items securely in place