The Olfa heavy-duty compass cutter is designed to cut circles from approximately 3" to 12" in diameter. It easily adjusts to accommodate user requirements. For example, the Olfa compass cutter is perfect for scribing circles necessary for the installation of recessed lighting. Besides scribing drywall, the cutter can cut or mark cardboard, mat board and thin plywood. This cutter uses super-sharp, heavy-duty snap-off blades that allow you to simply snap-off a dull cutting edge and advance the new cutting edge. Product info video.