Package Dimensions:20.32 x 12.7 x 5.08 cm; 109 Grams Batteries included?:No Batteries Required?:No Item Weight:109 g Floating Shelf Brackets's SIZE 4 by 1/2 inches approx. Shelf Floating Support work well only when you can attach the base to a stud. Just make sure you drill deep enough for the supports. Blind Shelf Support - A drill and chisel to get it level and fit snug against the wall. Floating Shelf Bracket works perfectly to turn an old reclaimed barn beam into a floating shelf. Enhance the flexibility of space. Floating Shelf Bracket is adjustable in both directions,easy to assemble on the wall. See more product details Floating Shelf Brackets's SIZE 4 by 1/2 inches approx. Shelf Floating Support work well only when you can attach the base to a stud. Just make sure you drill deep enough for the supports. Blind Shelf Support - A drill and chisel to get it level and fit snug against the wall. Floating Shelf Bracket works perfectly to turn an old reclaimed barn beam into a floating shelf. Enhance the flexibility of space. Floating Shelf Bracket is adjustable in both directions,easy to assemble on the wall.