The Tripp Lite 16U521 is a 19-inch open frame rack enclosure cabinet with adjustable mounting rails. It has a height of 21 inches, width of 19 inches, and depth of 21 inches. The 16U521 features a steel construction with lockable, removable side panels and vented top and bottom panels. It has adjustable mounting rails that support 4-post mounting and includes 50 #12-24 equipment mounting screws. This rack enclosure cabinet can be wall-mounted or floor-standing and has a weight capacity of 200 lbs. The 16U521 provides an open frame rack solution for mounting telecom, A/V and networking equipment.