Power By 2x AAA Batteries (Not included), Size 36mmx 88mmx 15mm / 1.41″x 3.46″x 0.59″, Relative humidity < 90%RH, Emission Frequency 433MHz, Detection Angle Horizontal Plane, Working Temperure -10℃~50℃, Name 433MHz Wireless Water Leakage Alarm, Working Voltage 3V, Quiescent Current 10uA. Check coupons or create price alert down below. Let’s see what best price is ATM.
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. ($13.59): BGSmart6
apply code in your basket (cart) after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): affiliate6, bgssaff9, aff7off, BGaDmITAd, bgchinafest, BGDigoo15%, BGDG15, BGSAMH, 20%DG422, BGSMOFF, BGDGASG, BGSAMRTH, BgcLuBofErtA10, BG15SH12, BGSTHO15, BGHONEY2110, BGSHOM15, BG6c046a, 13f142, BGSHE15, BGISOG753, BGedb972, 6GSGIT, BG4fcf10, BGD11073, BGf27012, BG4a4559, ADMITAD2212
(there’s a little possibility that old coupon will work)
Price history and price alert
Do you need price history chart (for all/most countries) for Digoo DG-HOSA 433MHz Water Leakage Alarm? There we go. The lowest price was: $7.99.
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)).