Immersion monitoring, timely alarm by App, IP67 waterproof grade, Note: the CR2032 battery is included.
Go down and check coupons out. Remember to check price history if it is available. Do you want to know what the best price is?
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 and price update (UTC):
Banggood
Banggood warehouse is located in China. You can get coupon down below.
Link: Banggood product page
1. ($25.49): tRaDetRaCKeR
apply it in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/i1u
Old coupons (from the oldest to the newest): 10XMA, affiliate6, aff7off, BGaDmITAd, bgchinafest, BG11GR06, BGBFAFF2019, BGCITYADS2019, 13f142, BG9NY, bGpAnDacHeCk, 2020CNY, BGAQ20, BGSAMH, BGAQA15, bGhOnEy10, BGSM15, BGSMOFF, BGAQWD7, bgshOOp10, BGAQWAUK, BGSAMRTH, BGELIG0920, BgcLuBofErtA10, BGAQWDE, BGAQWLECZ, BG15SH12, BGAFF10OFF, BGSTHO15, BGAQSUK, BGCuponation10, BGHONEY2110, BGSHOM15, BGGR504, BG282887, BGCL504, BG068dae, BG9abad6, BGcd45a7, BGc77aed, BGD11051, BGB5063, ADMITAD2212, BGf95b03, BG326e94, BGSmart6, BGa51b76, BG2fe0c5, 8BGwbg2204
(there’s a little possibility that old coupon will work)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – Xiaomi Smart Water Sensor [EU] ($-3)
Price history and price alert
Check out price history chart (for all/most countries) for Xiaomi Smart Water Sensor. The lowest price was: $6.99.
Price records source(s): Gearbest, 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)).