SS. The V42 (formerly K42) is the best-selling codelock in the world. It is compact and easy to use with a modern design that is suitable for either indoor or outdoor mounting. The V42 has a capacity of two four-digit codes. One can be used by residents while the other is used by the property caretaker, for example and all settings are made directly in the unit.. Backlit buttons. Programming done internally (jumper pins). Lock open time 1-30 seconds. High security keys required for code change