Olfa Safety Knife - Spring-activated blade automatically retracts when cutting is paused or stopped Blade retraction cannot be overridden, even when blade slider is engaged Oversized, textured slider for easy activation Sturdy aluminum nose reduces handle wear-and-tear to prolong life Exclusive Dual-Edge Safety Blade with 90-Degree Edge delivers unmatched sharpness and reduces punctures Flip blade for right- or left-handed preference