Equipment Interface Module, Wireless, For Use With (G2657627)Th6320R1004 Or (G2731626) Th5320R1002 Wireless Focuspro Thermostat, Controls Up To 3 Heat / 2 Cool Heat Pump Systems Or Up To 2 Heat / 2 Cool Conventional Systems When Used With The Wireless Focuspro Thermostat, Color Gray, Height 8 1/8 In, Width 8 In, Depth 1 5/8 In, Operating Temp Range -40 to 165 F, Input Voltage 18 to 30 Vac