The RHEEM MFG COMPANY Mics-180 Ext. Controller (RTG20126B) is a sophisticated control unit designed for precise management of heating systems. This controller features advanced programming capabilities, allowing for customized settings to optimize performance. Its compact design ensures easy installation in various RHEEM models. Built with high-quality materials, it offers durability and reliability in demanding environments. This controller is essential for enhancing the efficiency and functionality of your heating system, adhering to industry standards for safety and performance.