Triac AT hot air welder has intelligent digital temperature control and blower speed control. Leister TRIAC AT Hot Air Toolkit with 3/4-inch (20 mm) nozzle is an intelligent hot air tool used for TPO/PVC single-ply membrane welding, vinyl welding, overlap welding, draw welding, and stitching. The Leister AT is the best hot air welder when accurate temperatures are needed. The unit reaches temperatures automatically and voltage fluctuations are compensated. Leister Triac AT hot air tool has adjustable heat from 104 degrees to 1148 degrees and air-flow control with a large digital display.