The RackSolutions Dell Precision Sliding Rack Shelf for PC will allow users to mount 3 Dell personal computers on one shelf This shelf is designed to fit the specific size of the Dell Precision 3420, Dell Optiplex SFF 3040, Dell Optiplex SFF 7050 and the Dell Optiplex SFF 5040 This self is also compatible with RackSolutions 1U cable management arm The RackSolutions Dell Precision Sliding Rack Shelf for PC will allow users to mount 3 Dell personal computers on one shelf. This shelf is designed to fit the specific size of the Dell Precision 3420, Dell Optiplex SFF 3040, Dell Optiplex SFF 7050 and the Dell Optiplex SFF 5040. This self is also compatible with RackSolutions 1U cable management arm