Self Retracting Safety Utility Knife, Durable Self Retracting Utility Knife Designed For Opening Cartons, Features Spring Loaded Blade For Secure Operation, Blade Retracts Into The Knife Automatically When Pressure On The Slide Button Is Released, An Interlocking Nose Secures The Blade Safely Between The Knife, Halves, Ensuring That The Blade Is Only Exposed When The Knife Is In Use, Durable Steel Handle.