40mm Wide Overlap Nozzle. Leister 40MM Wide Plastic Welding Slot Nozzle Push-fit with a screw to be able to tighten for a secure fit. Fits on a Leister Triac-S, Triac-ST, or Triac-AT Hand-Held hot air welder. Comes with Leister Triac ST Roofing Kit. This is the most popular tip for hot air roof seam welding.