The best smart door lock for building exterior doors: Gold warranty (one year) immediate replacement. Very high quality and upgraded features. Smart door lock for building exterior doors. Smart door lock. Elegant and modern design. Made of aluminum. Digital number screen. Voice prompts. 7 ways to open the door from the outside: PIN code. Magnetic card. Fingerprint. Mobile app. Normal key for emergencies. Facial recognition Hand wave unlock Key Features: Very high quality (first grade). Water, moisture, and dust resistant. Operates on 4 AA lithium batteries and can use portable batteries via a (USB) port in emergencies. The device can be connected to electricity instead of batteries (via a 12V DC adapter). Connect the device to Wi-Fi directly without needing to add other devices. Ability to open the door via the mobile app (Tuya Smart). Add up to 300 users. Ability to connect the device with a home intercom system (may not be compatible with some systems). Supports opening on both sides (right / left). Key functions of using the mobile app (Tuya App): Open the door lock directly from the app. Manage users. Live streaming at all times Log user entries and exits Package Contents: Exterior and interior handle. Includes batteries only if installation service is requested. Includes 2 magnetic cards and 2 normal emergency keys. Includes an installation guide for openings and screw locations to aid installation. Includes a complete set of screws required for mounting. Can be installed on any type of exterior door: wood, iron, aluminum, stainless steel. Warranty: One-year replacement warranty against any manufacturing defects. Does not include batteries or misuse.