This is a Venturi powered device guide for coring holes. You insert the bushing for the size hole you need and then attach an airline. The tool will vacuum down to countertop and help you start your hole without bouncing around on the top of the stone. It just works....keep noobs from trashing your tops.
This model hooks up to a shop vac. The cool part is the shop vac that provides the holding power can also capture the dust. Works on counters and for vertical applications like shower walls.
Super awesome for processing processing really hard procelain.