The Resideo AT72D1683 Multi Mount 40VA Transformer is a dependable component for many HVAC systems. The essential purpose of this transformer is to reduce the primary voltage to a level that is suitable to drive control circuits and other low voltage components in the system. The EA122A1028 is a multi mount transformer for installation versatility. The main voltage is 120 VAC, and the output voltage is 26.5 VOC, giving a power rating of 40 VA. The transformer is efficient at 50 and 60 Hz frequencies and operates from -20 to 105°F. Its small dimensions of 2.22" x 3.06" x 3.22" make it easy to integrate into many HVAC systems.