This shelf is made from a nice piece made of thick North Carolina Black Walnut. I sometimes think of these as "floating bricks" because of their lack of vertical supports and size. Hangs on the wall using two keyhole hangers embedded in the back -they hook unto screws driven into the wall. Overall dimensions: 21 1/2” Wide 5“ Deep 1 3/4" High 55cm by 14cm by 4cm