What are the CD weld insulation pins

What are the CD weld insulation pins and they used for?

CD weld pins are used for many industires all over the world,such Power plant insulation,Equipment insulation,Marine insulation.Weld pins are used for attaching insulation to various metals, with the use of a CD welder. After the pin is welded in place, the insulation is impaled on the pin and secured with a self-locking washer.