The best main smart door lock: Very high quality and advanced features. Smart door lock. Elegant and modern design. Digital number screen. Voice prompts. Doorbell to request remote opening. Anti-tampering and anti-theft alarm device 5 ways to open the door from the outside: Password. Magnetic card. Fingerprint. Mobile app. Normal key for emergencies. Key Features: Very high quality (first grade). Water, moisture, rust, and dust resistant. Operates on 4 AA lithium batteries and can use portable batteries via a (USB) port in emergencies. Connect the device to the app via Wi-Fi. Ability to control the device via the mobile app (Tuya Smart). Add up to 300 users. Key functions of using the mobile app (Tuya App): Open the door lock directly from the app. View previous usage history. Manage users. Warranty: Two-year replacement warranty against any manufacturing defects, does not include misuse. Device contents include: External and internal parts. 2 normal magnetic cards. 2 emergency keys.