The PUK4 is the latest generation of precision welders from Lampert. Developed by goldsmiths for goldsmiths - you weld, PUK4 takes care of the details. Weld on findings, easily add metal, weld adjacent to stones,weld silver (alloys), fill porosity, tack workpieces prior to soldering, weld seams, and much more – all no problem with the PUK4®.