The Rolls RMS270 rack tray is designed to securely hold two Rolls half rack products so they can be mounted in a single rack space. The RMS270 is designed to house any combination of the HR72, HR73, HR78, MX153 or HR155. It can potentially hold other products but you will need to drill mounting holes in the RMS270 or the product you intend to mount in the RMS270.
To mount the HR72, HR73 or HR78. You will need to use the internal (silver) mounting brackets and hex nuts - see below. These products mount to the tray from the side of the unit and are also held in place by the front.
First remove the bump-on's (bottom rubber feet) from the unit being mounted. Pull out the side screws in the unit being mounted (2 Large flat head screws per side). Then use the large flat head screws to attach the units to the RMS270 from the side. Use the small flat head screws to attach the front of the unit to the RMS270.
Note: When attaching the metal rack tray to plastic front panels, do not over-tighten the screws as they will easilty break the plastic front of the unit.