1.Material : Galvanized Solid steel. Will not get rust or bend.This floating brackets included 6pcs 2.Dimension: 70mm(L) x 75mm(W) x 14mm(H); Mount Hole Distance: 42mm 3.Advantage:Strong enough to hold your shelf steadily. Can be used in area with limited space, or hang a invisible shelf on wall. With premium finish and durability, this shelf brackets have better performance and it perfect to be your floating shelves helper 4.Kindly Note:We recommend mounting to a stud on your wall for maximum support. Each bracket holds 15lbs. For heavier shelves please add extra brackets to distribute the weight 5.Scope of use:Use a router to remove 42mm from wood. Made to completely hide behind your shelving, small profile for easy concealing