Throughout the years, we have added several features to evolve into what is now known as the SunRotor® Pump Controller. We are looking to clean our inventories on "no longer manufactured" products, which includes this generic pump controller that has all the functionality of the current controllers without the added features, such as speed control and low water timer. We have tested each and every one of these controllers, and each performs as needed for the SunRotor® Solar Pump line. These will only work for 24V, 36V, & 48V compatible pumps and configurations. Since these controllers are no longer being manufactured, the usual SunRotor® 5-year warranty will not be available, and they will be purchased AS IS. Because of this, we have marked these items down significantly. If you have any questions, please feel free to call us at our toll-free number at 1(866) 246-7652.