Modified in Tinkercad. This is only the case. Various covers can be found in the link for the original case made by Stamos. The bracket was remixed from prusa_i3_bear_upgrade/psu_upper_mount_silver.stl at master ยท gregsaun/prusa_i3_bear_upgrade (github.com) and is attached with two M3x10 screws and nuts to the case. You will also need an M5x10mm hex button head cap screw and a M5 T Nut to attach the assembled case to the frame. These roll-in nuts have worked well for me Amazon.com: uxcell Roll-in Spring M5 T Nut, Roll Ball Elastic Nuts for 2020 Series Aluminum Extrusion Profile Pack of 20 : Industrial & Scientific.
The author remixed this model.