Square Rack Mount

In the 4 or 5 months I've been designing things this is the longest project I have done so far. this is a square rack mount that I made to attach some things on to the rack of my marimba. I don't know if all square racks have the same dimensions; I know it will work on a Yamaha and Pearl square racks because I have used Pearl mounts on Yamaha racks in the past (and currently). I wouldn't put anything heavy on the mounts I designed: 1 because it is plastic and 2 because it potentially hangs ov