This is a quick install spring and washer desined to fit all models of the KitchenAid Mixer (minus the Mini). There are two pieces included, the spring and the washer. The spring and washer were both manufactured with high quality components and materials. The spring and washer was removed from all models of the KitchenAid Mixer around the year 2016 which left something to be desired for its users. We have manufactured the spring and washer which is a perfect fit every time! The installation is simple and requires no tools! Simply split the spring and thread it over the pin located on the agitator shaft of the planetary and then thread on the washer that comes pre split to allow for easy install. Addition of the spring and washer goes a long ways to protect and improve both the longevity and the function of your mixer!