Wireless Technology: ZB 3.0, Size Small Body: 25*10*9mm, Transmission Frequency: 2.4GHz, Size Main Body: 40*25*12mm, Working Voltage: 2.4V-3.3V(CR2032 battery), Transmission Range: Indoor: 10~30m/Outdoor: 30~50m, Working Temperature: ‒20°C ~+60°C; 0%~95%RH.
Basically copy coupon, view price history or create e-mail price alert. 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. I couldn’t find any coupon for this product on latest product update.
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!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/i1u
Old coupons (from the oldest to the newest): Cuponation9, BG864dcc
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Do you need price history chart (for all/most countries) for MoesHouse Tuya ZB Smart Window Door Sensor? There we go. The lowest price was: $6.99.
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)).