The Polymer Header Hardware Set if for use with Legacy™ Model LRZM, LRZE Pool/Spa Heater, LXi™ Low NOx Heaters. Jandy LXi Pool and Spa/Hot Tub Heater Jandy LXi pool and spa/hot tub heaters exceed environmental standards for Low NOx emissions. Lower emissions mean you can enjoy your pool or spa/hot tub with confidence, knowing your pool equipment is designed with the environment in mind. The Jandy Pro Series LXi comes automation-ready for easy integration with Jandy Pro Series AquaLink® controls and other control systems. Built-in freeze protection and exclusive "Maintain Temperature" functions are also available.