The PowerPinner 7300 is a capacitor discharge welder from Gripnail Corp. Solid state and portable, it is made to weld cupped head pins with shank diameters between 2 and 3.3 millimeters. The manufacturer says its strong and lightweight design makes it ideal for fastening duct insulation on a worksite or in a shop. Other features include a cooling fan, shoulder strap, a protective outer case and a dial-down DC voltage setting.