2 buttons: doorbell button / reset button, Audio output: 1 channel, SensorModel: GC0328, Infrared driver: 50mA max, Main control model: BK7252, Product Model: DoorBell, Photosensitive: support, Product Category: Smart Doorbell, Charging power supply: DC 5V, MicroSD card slot: not supported, Audio input: 1 channel, Indicator lights 2: device status indicator / charging indicator, Battery interface: 1 way.
Price history, coupons and price alert are available on this page. You probably want to know what is the best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. As you can see I didn’t find any active coupon for this product right now…
Link: Banggood product page
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BG00c906, BG589b2e
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Do you need price history chart (for all/most countries) for Wireless Video Doorbell 2.4GHz Camera? There we go. The lowest price was: $14.09.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).