This is a convenient method for rackmounting portable media players and docks. This versatile shelf can accommodate most MP3 players and satellite radio receivers and can hold one or more players. Grommets in the rear of the rackshelf protect cords and ease cable management. Racking Height: 7 inches (4 space) Useable Shelf Area: 17.38 in W x 5.86 in H x 5.33 in D. Finish: Black Brushed & Anodized