Rev-A-Shelf 5WB2-2122CR-1, 21 inch Double Pull-Out Chrome Wire Shelf. This roll-out drawer/shelf is perfect for mounting under the sink or in a base cabinet on fixed shelves. The 22″ full extension drawer slides allow full access. Brings your stored items to you so you don’t have to hunt and dig to find what you are looking for! Bottom mounting slides require only 7 screws to fasten to cabinet. Minimum Opening Width: 20-1/2″. Distance between shelves is 8-5/8″ or 11-5/8″, set during assembly.