Just replace the old door bell with this video door bell
Pros: - 2-way audio, 720p resolution - this is more than enough for door bell video -PIR motion detection - Day and night mode, good quality image at night or low light - Come with SD memory card, battery and charging cable. Just install this and let it run. - Waterproof
Cons: Not fully waterproof, IP55 rating may not sustain storm for long time? Only supports 2.4GHz Wi-Fi.
To be tested: Battery performance.
Overall this is a good video door bell at good price.