This is an add on to this awesome print, https://www.thingiverse.com/thing:3044898
It gives you a litte support for your hand/arm aswell as a hidden storage for your candy or whatever, and prevents The mouse from slipping around. Especially if you use tpu or some other rubber like filament.
No suports, just print.
Print lid in tpu or other flex lying upside down on bed.
The author hasn't provided the model origin yet.