Self-retracting safety knife features a revolutionary, heavy-duty, spring-activated blade that automatically retracts the instant it loses contact with the cutting surface, reducing workplace injuries. It includes a slip-resistant ergonomic handle and stainless steel blade channel that holds the blade tight. Cutting depth is 3/4". Knife is ideal for cutting corrugate, shrink-wrap, plastic strapping, rubber, leather, flashing and more. Self-retracting safety knife is for right or left handed use. It uses Olfa SKB (9613) blades (sold separately).