Leister ST Hot Air Welder with Pencil Tip nozzle. This Leister ST hot air tool is best used for TPO/PVC single-ply welding, vinyl welding, overlap welding, draw welding, and stitching for consistent reliable heat output. Leister ST will hold 80 different nozzles. Leister ST replaces the old model of the TRIAC S. A single dial on the back controls output temperature from 104° - 1290°F. Leister st hot air tool has a 2-component handle with the perfect balance that ensures an ideal grip for optimum working even under the toughest conditions. See our Leister Nozzles.