Shelfology: 3 Rod 34" Concealed Medium Duty Floating Shelf Brackets. Fits Hollow & Solid shelves. 1/4" thick steel black bar. Supports shelves 1-3/4 - 2" thick or more and from 7" to 10" deep. 80 lbs. capacity per rod. Screw holes are set 1" C/C from each end and continue 4" C/C down the length of the bracket. Rods are set 2" C/C from each end, 3/4" dia, and countersunk screw holes are 3/16" OD. Does not include shelf or screws.