Use this pulley to upgrade your industrial sewing machine with a cogged belt to the Sailrite^® Workhorse^® Servo Motor (this pulley comes standard with the Workhorse motor). This part can also be a replacement pulley for Sailrite ^®Fabricator^® and Professional Sewing Machines from 2017 or newer. The modified design of this XL 1/5th pitch timing belt pulley requires no set screws; instead, a keyway in the pulley lines up with a keyway on the motor shaft. Then a key is pressed into the opening. This key is not included.