Cloud Transformation - No SD card needed, all videos recorded by this wireless doorbell are stored in the clouds, which is more convenient to control Two-Way Audio - Designed 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 powered, you can install the doorbell camera next to your door with tape or velcro HUMANIZED AND MOTION - The wifi video doorbell tells you to keep an eye on supplies, monitor porch pirates, or simply check the weather, distinguish people and other movements accurately, the sensitivity is adjustable, real-time will be sent to your phone app 2 x 18650 rechargeable batteries