Circles Cutter Replacement Blade for Woodworking, Universal Cone, Perfect for Ceiling Boards, ALC, veneer, and more, Downlight Mounting, and even Woodworking Work. Drilling Size: 1.2 - 11.8 inches (30 - 300 mm); Drilling Depth: 0.1 - 2.0 inches (3 - 50 mm); Drill Diameter: 0.4 inches (9 mm).