Keyless Mechanical Keypad Code Digital Locker Home Entry Security Safety Door Lock Safe and reliable with zinc alloy integrative structure Fit door thickness: 35-60mm, suitable for wooden doors and steel doors, Not for standard door hole, Must be used on a new (uncut) door Very easy to operate, easy to installation Opened by code, great for office use, home or apartment Caution:please read the instruction thoroughly before using the unit.please retain this manual for future reference