STARK USA 16 in. 3200-Watt Circular Cut Concrete Saw Cutter with Water Line Attachment (No-Blade) 50120-H2 - The Home Depot
Amazon.com: OLFA Compass Circle Cutter (CMP-1) - Adjustable Compass Style Rotary Circle Cutter w/ 6 Blades for Cutting Circles Up to 6 Inches in Diameter, Replacement Blades: OLFA COB-1 Blades, Original Version :