Fangrui Product Details Compliant With Bluetooth 4.0 Ble Standard Support Intelligent Door Lock App For Opening Doors Built In Clock Chip Built-in Antenna Built In Passive Switch (relay) Note: 1. Below The Minimum Operating Voltage, It May Cause The Module To Malfunctionexceeding The Maximum Operating Voltage May Cause Module Damage 2. Generally, Modules Are In A Sleep State And Only Switch To Other States When Unlocking With The App 3. Extreme Environments Can Cause Modules To Malfunction Note:the Factory Batches Are Different. If There Is A Slight Difference In Appearance, It Does Not Affect The Use. Colour:green Material:plastic Size:38x27mm (excluding Lines) Package Contents: 1 * Electronic Lock Module 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.