Cloud Transformation - No SD card required, all videos recorded by this wireless doorbell are saved in the clouds, making it more convenient to control. Two-Way Audio - Equipped with a built-in microphone and speaker, you can talk to the island via the two-way audio function of this smart video doorbell with phone app, no matter where you are. EASY INSTALLATION - This wireless video doorbell is battery-operated. You can install the doorbell camera next to your door with adhesive tape or Velcro. HUMANE AND MOVABLE - The Wi-Fi video doorbell alerts you to keep an eye on supplies, monitor porch pirates, or simply check the weather. It accurately distinguishes people and other movements. The sensitivity is adjustable and real-time information is sent to your phone app. 2 x 18650 rechargeable batteries