ComfortLink II communicating technology connects all of your key components so your system automatically charges, configures and calibrates for optimal performance through the lifetime of your products. When the optional Telephone Access Module (TAM) is added, you can conveniently adjust settings and receive system updates by phone no matter where in the world you may be. With its fully modulating capability, you can achieve up to a 95% AFUE (annual fuel utilization efficiency). The XC95m’s variable-speed fan motor adjusts speed to provide a consistent flow of warm, comfortable air with quiet operation. There will be no more hot or cold spots in your home!