42,000/29,400 BTU ""Ultra" Series Communicating Econet Enabled Two-Stage Variable Speed Ecm Natural Gas Furnace, Volts:115, Hertz:60, Phase:1,Airflow:Multi-Position, Cfm:1050, Efficiency:96, Ignition:Direct Spark, Input Btu:42,000/29,400, Output Btu:41,000, Dims:34"H 17-1/2"W 29-5/8"D, Weight:128 Lbs, Origin:Usa, Lp Kit:Rxgj-Fp34 Not Included, Compatible With Single Or Two Stage Thermostats, Not Included. For Optimal Performance A Two Stage Thermostat Is Recommended