Check who's calling before opening the door! See clearly, day or night who's there and interact if you wish using the built in microphone. Takes pictures of callers whilst you are out, and the device is already paired - straight out of the box. Simply stick the doorbell on the frame, switch on the receiver and you are good to go - no tradesman, no computer, no subscription and no wi-fi required. Full instructions supplied. No more cold callers! Requires 4 x AAA batteries (not included) for the reciever and 1 x CR2032 battery (included) for the bellpush.