Features: Made of good quality zinc alloy and stable performance. Invisible remote control lock, specially designed for home security. No keyholes outside, there is no way for thieves. Tiger lock method, more safe and stable. Super design and easy for installation. Specification: Host Machine: Material: Zinc Alloy Size: 15.5 * 8 * 3.5cm Power Supply: 2 * AA batteries(not included) Transmission Frequency: 315MHz（±500KHz） Operation Range: Within 20m Unlock Mode: Remote control unlock& Mobile Phone Unlocking (additional Bluetooth adapter is required) Remote Controller: Color:Silver Size(Each): 6 * 3 * 1cm Battery(Each): 1 * CR2032 3V Standard Number: 4 (included) Max Controller Number: 16 (not included) Function: Lock & Unlock Package List: 1 * Lock 1 * Lock Body Holder 1 * Lock Catch 4 * Remote controller 1 * Bag of Mounting Screws 1 * USB Cable 3 * Fixed Sticker 1 * Manual