The Tray does its job. You can mount it underneath a RockBoard and it can hold a power brick or some pedals. However, I found that when combined with a RockBoard TRES 3.1 it leaves not enough room for an isolated power brick. So I cannot use it. Also the Tray is fastened using plastic screws, for one-time use. Why? And lastly, why isn't this just included with every RockBoard?