The Slice 10558 Smart-Retracting Utility Knife features our two newest innovations: Smart Retract technology and the Ergo Pull slider. This is our most advanced safety utility knife with multiple precautions to keep you injury-free. Smart Retract pulls the blade back into its housing as soon as it loses contact with the cutting material, even if you still have your finger on the slider. Ergo Pull reduces strain allowing you to slide and cut in the same direction.