Optional Add-on for 18650 specification batteries Optional Add On Available for Door DingDong Ring Belle and Memory Card! Optional Add On Available for Door Door Belle Casing Description: 1.If dont have any electric supply for the installed area, please remember to add on Battery! 2.Million HD pixels collocated with 166 degree wide-angle lens 3.Support mobile phone remote fast wake up device within 1 second. 4.2.4G Wi-Fi connection 5.High quality two-way talk with noise cancellation 6.Support PIR motion detection, when someone hovers at the door, immediately alerts push notifications to the mobile phone. 7.Day and night mode automatic switching, whether day or night, the image is clearly visible, for your safety and family security Specification： Resolution: 1280*720 Field of Angle View: 166° IR LED: 6*850mm Wi-Fi: IEEE 802 11 b/g/n Audio: Two-way talk with noise cancellation Recording: Device SD card recording(20 seconds) Storage: 16G/32G/64GB(not included) Battery: AC Input/3 x 18650 specification batteries(total 6800mAh, work regularly for 6 months.)-Optional Monitoring: Device Button, Motion Detection, Remote Live View Notification Function: Push Notifications within 1 second Device Wakeup: Within 600 ms Power Consumption: Power Consumption Standby 200μA, Working 170mA Packing List: x1 CCTV Doorbell x1 Screw Set x1 Double Side Tape x1 User Manual