The BGR-ISO-Z4 Electrically isolates the rack from the floor, with seismic mounting. The Middle Atlantic BGR Series is the next generation rack, designed with significant installation and performance benefits by providing more rackspace in a smaller overall height than similar racks and all BGR Series racks are Seismic certified with an Ip value of 1.5 when used with the BGR-Z4 or BGR-ISO-Z4 option. The Pre-threaded ganging holes allow for rack joining after loading making it a breeze to expand your operation without shutting down! Also includes 1/2”, 3/4”, 1” & 1-1/2” electrical knockouts and 5/8” and 1/2” D UHF/VHF antenna knockouts on rear top & bottom, easily removable for cable pass-through. Top cable management plate (38 space and up) includes 1/2”, 3/4”, 1” 1-1/2” & 3” electrical knockouts and 5/8” and 1/2” D UHF/VHF antenna knockouts. There is also an optional stackable 3” extender bay available for front and rear and optional curved and beveled front doors in solid, vented and plexiglass styles with a configurable open top with vertical cable management entry points. This is NOT the rack of the future it is the rack of NOW!