Multiple Ways to Unlock - Unlock via the keypad, the eufy Security app, or one of the 5 included keys. Internal door sensor for automatic locking. Security you can trust. BHMA Grade 2 security certification. Control up to 45 metres away via the ultra-stable Bluetooth 5.0 connection. Durable and proven to work after lockingand unlocking 250,000 times. Works in Extreme Environments Build to withstand temperature extremes between -30°C and 70°C. Your Information Remains Private. Bank-grade encryption chip ensures your in-app data is kept private. Password Protection, hide your password from prying eyes by scrambling your password. Emergency Unlock Plug, unlock your Smart Lock using a portable charger when it is out of power.