The Universal Shelf System is designed to create floating shelves and be installed in ceiling joists to create open kitchen shelving using 3/8" lag screws. Add your own shelving board in 11-7/16" width to create a one of a kind shelving system. Set at no greater than 48" span, a pair of the universal shelving brackets will support up to 200 pounds. Create a custom desk or bookcase/shelving unit by installing on the floor. Attaching shelving boards using the 1" slots gives the unit stability and a carrying capacity of 350 pounds per pair when spaced at a 48" span or less.