Series LT/LTX/LTXR two-stage infrared heaters are designed for low-clearance applications. According to the manufacturer, the principal advantage is the softening of the radiant output over a much longer length of tube with an end-to-end variance of less than 15 percent and remarkable bottom clearance of only 36 inches. The infrared tube heaters are available in outputs ranging 40,000-100,000 Btuh and in lengths of 30-50 feet. Two gas options are available: natural gas and LPG. The two-stage units include a high-low output capability allowing for quicker recovery on the high fire and economical steady operation on the low fire.