1. Invisible lock, installed inside the door without exposed lock holes, not visible outside the door 2.Mechanical lock+remote control lock=0 stolen 3.Intelligent dual battery pack low-voltage protection function 4.High security and anti-theft level 5.Humanized mechanical emergency unlocking<br><br>Lock body parameters Remote control distance: 10-30m Anti theft performance: anti tin paper unlock universal key Power supply: 4 AA batteries (shipped without batteries) Backup battery: 23A12V battery(shipped without batteries) Usage environment: -20 ℃ -80 ℃, temperature 5% -60% Acceptance frequency: 433MHz (+-500kHz) Unlocking method: remote control unlocking/indoor manual unlocking/emergency unlocking Remote control parameters Remote control function: unlocking and unlocking Standard quantity: 4 (can be freely increased) Battery model: 1 2032 battery Transmission method: frequency conversion signal each time, preventing duplication Working humidity: Temperature 5% -90% A maximum of 32 remote controllers can be registered simultaneously Due to different batches, there may be differences in product appearance and printed text, which will not affect use Colour:As Shown Material:zinc alloy<br><br>Package Contents: 1 x door lock 4 x remote control(Built-in battery)<br><br>Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.