HEWLETT PACKARD Compaq Comp. STABILIZER FEET OPT KIT-10000 SERIES (246107-B21)
Stabilizer Option Kit 600mm wide, 10000 Series 246107-B21 An anti-tip stabilizer provides stability and support when equipment is installed, removed or accessed within the rack. It is recommended you use a stabilizer option kit with a stand-alone rack.
I do not know if this works with other racks, probably .
I know it is heavy, about 50 lbs.