Leister TRIAC ST heat gun hand tool is a hot air tool deployed worldwide. Triac ST Heat Welder by Leister is the best TPO roofing heat gun. Temperature °F 104 – 1292. Leister TRIAC ST replaces Leister TRIAC S. Triac ST will hold 80 Leister nozzles. This Leister TRIAC ST hot air welder comes with free 3/4" (20mm) nozzle and carrying case visit. Leister Triac St Hot Air Welder on DRPFastShip.com. This item has Free Shipping.