The telecommunications rack shall meet EIA/ECA-310-E standards, be 45 or 52 RU, constructed of steel and capable of accepting 19" wide EIA equipment. The rack shall include adjustable front and rear equipment mounting rails. The equipment mounting rails shall be #12-24 or cage nut square opening style mounting. The adjustable equipment mounting rails shall include printed rack unit numbering and can be flipped by the user for either numbers up or numbers down. The rack shall accept shelve units and equipment brackets. The front and rear structural posts of the rack shall be capable of mounting NetRunner ™ or PatchRunner ™ Vertical Cable Managers and accessories such as power outlet units, slack spools, zero RU brackets, thermal ducting and vertical filler panels. The rack shall also accept optional casters mounted to the bottom of the rack. The construction method shall ensure an electrically bonded structure for ease of grounding.