The SRP Modulus adaptive modulating infrared tube heater provides unparalleled thermal efficiencies in excess of 80%. Rates range from 80,000 to 200,000 Btu/hr with a 40% modulating differential. The built-in “Quick-Start” function ramps up to high power resulting in optimum temperatures achieved almost as soon as the heater is turned on. Available in lengths of 20’ to 60’, NG or LPG.