This is a cooling pad to have your laptop on your lap and still get plenty of air. It's large, so you need to print it vertically, and at an angle. I'm not sure if it will fit on a Prusa MK3.

Parts:

2 x 92x14mm Noctua case fans: https://a.co/d/40s277G

A USB A to dual 12V step-up converter: https://a.co/d/4tqTiyd

The Noctua's come with ‘silent’ adapters which you must use!! If you don't, the fans will draw a bit too much power and potentially damage your laptop!