Alarm Pedometer Countdown Sport Watch 50M Waterproof.
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.
Link: Banggood product page
1. ($35.05): BG1efeb0
2. ($35.43): Terence
3. ($35.43): 2203ActiesNL
4. ($35.81): BG00c906
this code has to be applied 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): men15, BGPMARS, 13f142, BGHONEY2110, BGCNNE9, BG43014, BGJWMEN15, BG33c3bd, BGd2eadf, 00c906, ADMITAD2212, 2022ACTIESNL, Tabby20
(these coupons are old, so probably won’t work)
Price history and price alert
Price history (for all/most countries) for NORTH EDGE Mars Watch is here. The lowest price was: $18.99.
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)).