We sell these for the for the ProRMK chassis. Part # 377288 or Gates Part number 44C4553. I used on my Pro and my Axys last year. Never lost any RPM or broke one. Saves some money in the process.
https://www.gobigparts.com/GATES-G-FORCE-C12-CARBON-DRIVE-BELT.html
Select part number from pull down menu.
https://www.gobigparts.com/GATES-G-FORCE-C12-CARBON-DRIVE-BELT.html
Select part number from pull down menu.