Features: 4 Blade positions with string cutting feature Change blades without opening the knife Thumb rest for greater control Preferred for cutting and scoring fiberboard, linoleum, wallboard, roofing and many other materials Durable, all-metal knife body construction Quick one-button blade change - no tools required Interlocking nose design helps secure blade and helps prevent body separation Integrated string cutter when blade is retracted Comes with hang-hole for adding a wrist strap or lanyard Swing-out blade storage for easy blade access 3 heavy-duty blades included (Stanley #11-921). Retractable Blade Positions: 3 Works with most standard utility blades