Zico Zi-4017 18mm Ratchet-Lock Rubber Grip Utility Knife Professional strength stainless steel blade channel secures blade for the toughest of cutting jobs. Blade is made of high-quality SK-5 grade alloy steel and designed for unparalleled sharpness and superior edge retention. Long lasting and durable - a new sharp edge with just a snap. Including 2 spare blades inside the handle, tool-free blade change. Great for cutting paper, cardboard, roofing, drywall, vinyl, acetates, etc.