OLFA-The patented ratchet mechanism of the Circle Cutter makes cutting circles easy. Cut perfect circules from 1.875 to 8.5 inches in diameter. Features built in blade cover for safety and a plastic guard to cover the pivot spike when not in use. Great for fabric, paper, vinyl, film, leather or more. For right- and left-handed users. Includes RB18mm blade. Fits RB18 Blades.