The Police 4 is the largest member of Spyderco's select family of lightweight knives featuring Bohler K390 tool steel blades. Ideal for extreme cutting challenges, it combines the toughness and superior edge holding characteristics of K390 with all the proven qualities of this highly refined design including the low-friction edge geometry of a full-flat-ground blade, a fully accessible Trademark Round Hole, a high-strength back lock mechanism, and a four-position pocket clip.