The Gator Cases GR-FS4B4739MDB Floor Standing Rack (47U, 39" Deep) has a powder coated finish over 18 gauge removable side panels with spring latch and an 18 gauge SPCC cold rolled steel top and bottom. It has a perforated top, M6 rack rails, adjustable depth front rack rails. The rack U number is printed on the rack rails. The rack has 1/2, 5/8, 3/4, 1.0 and 1 1/2" cable entry knockouts on the top and bottom. The 5/8" knockout design can be used for a VHF/UHF antenna. The front door features toughened glass with vented sides and spring loaded "push and turn" locking system.