BST7001A automatic hot air welding machine is a walk-behind welder for automated roof membrane seam welding. It is220-240VAC, 50-60Hz, 4200 watts, and provides consistent wrinkle-free welding on all types of roofing membranes. It uses a step-less adjustable temperature from 50 to 620C, adjustable speed of up to 2-15meters / minute and a digital readout of temperature and speed.