The Window Accessory plugs into a wall socket. Your Circle 2 camera body fits inside, and you set the camera settings in the Logi Circle App for Window mounting. There are free apps for PC/Mac and mobile. The camera works with a cloud subscription; the free level saves 24 hours, and the paid levels store up to 31 days and unlock more motion-activated screening features. The cameras and app work well if you have decent wi-fi, and everything is easy to set up.