With the addition of optional Seismic Bracket, SBK-700, 700 Series Racks can be certified in accordance to the Telcordia NEBS (Network Equipment Building Systems) GR-63-CORE standard. When the SBK-700 brackets are properly installed, the 700 Series racks successfully endured the rigorous real-world dynamic test - the racks are able to withstand up to a zone 4 earthquake which is comparable to Richter magnitude 8.0!