From CIOKS:
GRIP is a small metal clamp which you can attach to your DC7, ADAM or DC5 via the mounting holes and this allows you to mount the power supply securely underneath Pedaltrain boards simply by attaching the device and tightening two screws (which are included of course) without having to drill holes or use any other kind of tools. GRIP also allows you to move the PSU really easily if that is required.