Simplicity 420 is a 2-speed pulley kit compatible with Simplicity 515 & 616 tractor models. This kit allows for the adjustment of the transmission drive belt speed, providing greater versatility and efficiency in various operating conditions. With the ability to switch between two speeds, users can optimize their tractor's performance for different tasks, such as mowing, tilling, or snow removal. The kit includes all necessary components for installation, including pulleys, studs, a shifter yoke, and a pivot bracket assembly.