Here's how it works the cooling of T150 Before After The two holes are 4mm. One hole 4mm. The holes in red are enlarged to 3mm. The hole in blue is enlarged to 4mm. These holes are 4mm. After this mod I can play 4-5 hours nonstop at high force feedback settings without overheat. Remove the top cover before drilling the holes! When you are not playing you must cover the wheel to prevent a dusting! Attention,this mod will void your wheel warranty!