Complies with Bluetooth 4.0 BLE standard Support smart door lock app for opening the door Built-in clock chip Built-in antenna Built-in passive switch (relay) Note: 1. Lower than the minimum operating voltage may cause the module to malfunction Exceeding the maximum operating voltage may cause damage to the module 2. The general module is in sleep state and only switches to other states when unlocked with the app 3. Extreme environments can cause the module to malfunction Note: Different factory batches, if there are slight differences in appearance, it will not affect the use. Color: Green Material: Plastic Size: 38x27mm (excluding wire) Package Contents: 1 * Electronic lock module Only the above package contents, not including other products. Note: Light reflection and different displays may cause the color of the items in the picture to be slightly different from the actual object. The measurement allowable error is +/- 1-3cm.