With this gear you have the most likely spare part to fix drive problems of your kitchenaid kitchen machine. This gear is deliberately the weakest point of the drive to avoid greater damage to the machine if the stirring gear is used by, for example, to rapid operation or stirring quantities/stirring weight. Suitable for the models Kitchenaid Classic, Ultrapower, Heavy Duty, Professional and Artisan. You can find detailed instructions on changing the gear set https://www.youtube.com/watch?v=veciivpt7hk In terms of color, there is batches in yellow or black for the gear. We deliver in color to availability. Both variants are 100 % original kitchenaid / whirlpool. In Terms of Color for the Worm Gear, there are batches in Yellow or Black. We deliver in Different Colors According to Availabili.