This regal iron black Ashfield leverset is for use on exterior doors where keyed entry and security is needed. Both levers are locked or unlocked by key outside or turn button inside. 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. This leverset easily installs in minutes with just a screwdriver and works with door thickness: 1-3/8" - 1-3/4".