Weiser's SmartKey re-key technology provides you the flexibility to re-key your locks quickly and easily without removing them from your door. Plus SmartKey cylinders represent a quantum leap in security as compared to traditional pin- and-tumbler cylinders. The lock cylinder uses two steel balls inserted into the front of the key face to resist attack from drilling. They boast Grade I security with a 1" full bolt and titanium alloy throwbolt core. Each deadbolt has 'free' spinning guards to deter wrench attacks, anti-pry shields, anti-pick top pins, along with ball bearing embedded cylinder cores for uncompromised security. Grade 1 security is the highest level of residential security available. Added benefits include concealed screws and easy installation; an ADA turn-piece; iron black finish; and lock works with door thickness: 1-3/8" - 1-3/4".