The Taco Variable Speed Solar Control Circulators combine the advanced features of our external speed and solar controls with the reliability and convenience of our 00® Cartridge Circulators. All the wiring for power and sensors is done directly to the Circulator while the LED status panel makes it easy to check functionality. Dip switch based user configurable settings makes for a fast set-up, no matter the solar application. The Circulator continually adjusts its speed, maximizing the output of the collector, increasing the usable higher temperature water throughout the day, eliminating short cycling and increasing system performance by 20%.