The auto-lock mechanism of thisAce 9 mm Snap Off Utility Knife allows you to make quick and secure changes to the cutting depth with just one hand Commonly used for window film and tint preparation High impact ABS plastic handle with anti-slip rubber inset for secure handling Includes screw blade-locking mechanism to secure blade while cutting Grooved plastic body for grip to ensure comfortable use The locking mechanism can withstand high pressure Cuts on cardboard, plastics, foam board, gator board Dual button lock switch that uses #60 carbon steel blade with 7 snap offs