NOTE: With WIFI Adapter, can achieve remote control the lock by phone APP. Features: *No lock hole design, it completely abandons the traditional key and lock, open and close by remote control or phone APP (Tuya / SmartLife), realized real security. *Tiger lock method, more safe and stable. No keyholes outside, there is no way for thieves. *Add USB external power source function. Make sure the lock works when battery was dead (battery not included). *Three unlock modes optional: Phone APP unlock, Remote control unlock, Indoor emergency button unlock. *Easy installation on all kind of doors, very convenient. Specifications: Host Machine: Power Supply: 2*AA batteries (not included) Transmission Frequency: 315MHZ (500KHZ) Operation Range: Within 15m Unlock Mode: APP unlock&Remote control unlock& indoor emergency button unlock APP Support: iOS/Android Color: Silver, Blue with Silver, Blue with Gold (Optional) Item Size:15.5*8*3.5cm Item Weight (without accessories): 529g Remote Controller: Quantity: 2PCS, 4PCS (Optional) Power Supply: Lithium button battery (included) Function: Lock & unlock Item Size(Each): 6*3*1cm Item Weight(Each): 25g Package List: 1* Lock 1* Lock Body Holder 1* Lock Catch 1* USB Power Cable 2/4 Optional* Remote Keys 1* WiFi Adapter 1* Bag of Mounting Screws 1* User Manual(English)