The Tray is practically a mandatory addition to a Rockboard pedalboard, for attaching the power supply below the board. The plate itself feels sturdy, and it was quite clear how to attach the plate to the pedalboard. However, it was not clear how to attach the power supply to the plate. I have a 1Spot CS7 and after some thinking, I ended up attaching the 1Spot with a pair of cable ties to the Tray. Not pretty, but works. After this, the power supply fits neatly under the pedalboard (Quad 4.2).