I tried cutting over 20 circles in 1/4", 3/8, 1/2" plywood and in 1/2" pine stock - just won't cut a clean hole - always tends to spiral towards the end of the cut.The attachment is made plastic and is not designed to do anything near 'precision work. Maybe its OK for drywall.The instruction say to rotate the gizmo clockwise but the accompanying picture shows the a arrow going counterclockwise - either way the cut drifts outward as the cut goes to completion. The attachment fits nicely in the Rotozip carring case - I hope the whole thing sells well on eBay.