Square hole (cage-nut style) on EIA Standard spacing. DRK Series Cable Management Enclosures, 30" wide profile supports high-density cable management, UL Listed in the US and Canada, Fully welded construction provides: Static load capacity: 10,000 lbs., UL Listed load capacity: 2,500lbs., Seismic Certified load capacity: 815 lbs., Seismic certified to the following codes and standards: 2007 & 2010 CBC; 2006, 2009 & 2012 IBC; ASCE 7-05 (2005 Edition) & ASCE 7-10 (2010 Edition) and the 2006 & 2009 editions of NFPA 5000 for use in areas of high seismicity Zone 4 or Seismic Design Category (SDC) "D". These are designed for Mission Critical and/or High-Importance Installations in locations with the highest level of seismicity and top floor or rooftop installations including those within UBC and CBC Essential facilities or IBC, ASCE 7, and NFPA 5000 Seismic Use Group III facilities. For all codes, the Importance factor (Ip) is 1.5. Seismic Certified load capacity of 755 lbs. when used with DRK-Z4 seismic floor anchor brackets, 30" OD width. 31-1/2", 36" and 42" OD depth, OSHPD approved for fixed equipment anchorage in California healthcare facilities, 1/2", 3/4", 1" and 1-1/2" electrical knockouts found on removable split rear plates, top knockout plate additionally includes UHF/VHF antenna knockouts, Factory configured 19" EIA panel width DRK enclosure additionally outfitted with pair of keylocked side panels, plexi front door and leveling feet, 10" fan top with guard, available for easier ordering and to save installation time (DRK19-44-31K), 19" EIA panel width enclosures come standard with two front-mounted vertical cable ducts featuring abundant cable entry points and a full-length hinged door with three-point magnetic catches, Standard vented rear door is reversible to allow opening from either direction, Vented, plexiglass, and vented-plexiglass front doors available, Top accommodates 10" fan and includes fan guard for ventilation, Includes 100 rack screws, Stud in base of enclosure facilitates the proper grounding and bonding of electronic equipment, as per NEBS and NEC standards, Durable black textured powder coat finish.