I have previously written of the grozing iron I made, poorly, for A&S work. To compare, this one is MUCH easier, almost effortless to use. My "dremel" iron was much narrower and took more wrist force to chew into the glass. This is proper stock with a wider gripping face and more weight. I also noticed this generates a fair cloud of glass dust! Use under proper ventilation, outdoors, and/or wearing an appropriately-rated respirator!!
A quick video of me using my grozing iron: