of a rectangular protrusion 225 on the front surface of the back cover 212 and a mating latch structure 226 on the front cover 210 the directional arrow in fig1 shows the direction that the back cover 212 is mated with the front cover 210 which involves pushing the back cover 212 such that the protrusion 225 and the latch 226 mate once these devices are mated the back cover 212 then rotates with its point of rotation being the interface between the rectangular protrusion 225 and the latch 226 until the cover is properly in place using the protrusion 225 and latch 226 on the back cover 212 the preferred embodiment requires only one screw not shown to hold the cover 212 in place this screw extends through reinforcing member 228 of the back cover and into reinforcing member 230 of the front cover 210 referring now to fig1 there is shown a connection area 231 including a set of electrical contact pins 232 a and b this connection area 231 may be part of a backplane board 40 a c or may be mounted on a structural member on the rack e g a metal brace extending across the back of the rack regardless of its location the connection area 231 is where the cable end housing 231 preferably couples to transfer dc power to the racks 10 a c.