The Milwaukee Hand Tools Self-Retracting Safety Knife uses a self-retract mechanism, so the blade retracts when the button is released. There are 2 blade positions allowing for different cutting depths. The tool-free blade change saves time when changing blades. It has a thumbscrew mechanism that allows the user to change the blade quickly and without any extra tools. The heavy-duty metal body is highly durable and the wire stripper eliminates the need to look for another tool. It can cut a wire up to Ø5mm.