Print however you want to, my settings were pla .4mm nozzle with .15 layer height. The circular hole is designed to accept a 6mmx2mm magnet glued in place(there is a magnet in the mouse so really any small piece of metal glued there should work). May want to add ptfe feet to the bottom of it to maintain the smooth movement
Note: v6 is a smaller version with only one attachment point
v7 is slight larger and wraps around the mouse
The author hasn't provided the model origin yet.