Two ways to open the door: Code or Key Cast alloy integrative structure, firm and durable Master code can be used to add or delete any user codes Very easy to operate. One-key opening function: freely press any key to open the lock. Panic exit function Master Code can set valid time period for all user codes to unlock. Input wrong passwords for three continuous times, it will stop for 10 seconds without any operation. Automatic lock after unlocking in 5 seconds Audible tones for lock, unlock, jam and low batteries. 2 Years Manufactures Warranty Suitable door thickness:30mm to 50mm Features: 1 programmable master code, and 199 programmable sub-codes (for employees or guests).