The core of the tool is a milled angular in PTEE (Teflon) with threaded holds for the juncture of individual or pre-fabricated fixing devices. With this system the pieces to be welded are perfectly fixed at 90-degree and both hands are free so they can proceed with the welding. Teflon can resist to a temperature of 400 degree, and thanks to its low conductivity it does not take away heat from the welding point. However, the tool should be use for soldering-iron welding only, not to be used for forge welding due to its temperature limitation.
(courtesy of zclub 92)