Laykor 6600-88 Digital Keyless Electronic Pad Door Lock, Left Hand, Silver 1 Programmable master code, and 199 programmable sub-codes (for employees or guests) Schedule entry function for different users 2 Mechanical override keys included 2 Backsets included: one for 2 3/8" and one for 2 3/4" Weatherproof: anti-moisture, anti-dust, suitable for exterior doors under all weathers