GRS Gravermax / Gravermate Large Handpiece
Very powerful. It's designed for heavy metal engraving, wood carving, and other demanding jobs. The 2 jaw chuck holds tools from 1.6 to 4.8mm round or square. Even holds standard gravers.
The handpiece is 5.7" long and weighs 7.4oz.
This is a brand new handpiece, but it is an older, discontinued tool.