Spring Blade

A folding blade held closed by an internal spring under tension, releasing to a locked, fully extended position the instant a button or lever is triggered - far faster than manually unfolding a standard folding knife. That speed of deployment is its entire appeal, turning a closed pocket knife into a ready weapon in a fraction of a second.

Its blade length and durability are generally more modest than a fixed blade of similar size, a trade-off most wielders accept in exchange for that instant readiness.