This kit is for rack mounting a single TAMB2 unit. Screw the RPK91 rack mounting brackets on to the sides of the TAMB2 using the screws provided with the TAMB2. Once the brackets have been secured, the unit can be attached to the rack (rack screws are user-supplied). The RPK91 brackets can be similarly mounted at the back end of the TAMB2 if a rear-facing orientation is desired.