2. Place the top half of the clamp on the rack and install the Clamp Bolts. Tighten until you cannot move the clamp assembly. TOP PLATE: The top plate of the JHDRMT can be mounted using any one of the three mounting holes across the top of the plate, for added flexibility. The mount comes fully assembled utilizing the center mounting hole and may not need to be changed. This will depend on the location you chose to attach the mount to the rack and where you want the radio to be placed. To adjust