All information is in the pictures including the manual. My input after testing: Scan the 2D barcode to download and install Kement app from app store. The app will let you pair your phone with the camera. I tried with my iPhone and the camera was paired easily. You don't need to sign up for any cloud service to use the app. On your phone, you need to enable "notification" for Kement app so that whenever some one ring the door bell, you immediately get notification on your phone. Then you can use your phone to view door bell camera and talk to your visitor via the app. Update 1: The app stores captured pictures on my phone under an album bearing its name. Works with 2.4G WiFi (most smart devices need 2.4G) and your home WiFi should have it. Charge through type C port 5V/1A. The camera is supposed to work 10 hours with a full charge. However, you can use a USB-C cable to keep it powered forever. The manual doesn't have installation instruction, but it's very simple. The back of the camera is a mounting plate which can be pushed out /removed and attached to a door/wall with 2 screws. Note the mounting plate must be on a flat surface, can not recess. It does come with a double sided mounting plate, also services as drill board for mounting holes. Pare with the chime: Hold on the button on the chime and the doorbell button simultaneously to pair them. You may need to try a few time but it will pair. I rang the bell and the chime would sound up in another room at the other end of the house. The chime volume is not adjustable. It's set at quite loud volume for your whole house to hear it. You'll need a USB plug for the chime to be powered. It's not Ring door bell camera. But it does a decent job and cost so little. Update 2: added inside circuitry pictures of this camera to show the design details. You can see the battery, camera and antenna etc. Let me know if you have any questions or concerns. Update 3: This is a mini size doorbell, comparing to the other brand, see the picture. Update 4: if you worry about that the camera might blow up like the Gold Apollo pagers, you can open it up and remove the batter. It's very easy to open and put back everything. But if you remove the battery, you'll need to use cable to keep it powered to use it.