This rack shelf is compatible with 19" server racks from manufacturers such as Dell, HP and IBM. This rack shelf can be installed into racks with square, round or threaded holes. Rack mount equipment weighing up to 150 lbs can be installed using this rack shelf. The rack shelf is 24" deep (There is also a 20" deep option) and can be installed in server racks with installation depths up to 30" and in multiple configurations.