Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. So I have checked for active coupons (all category coupons and old ones), but there was no working coupon in Banggood.
Link: Banggood product page
Price: -3 USD
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
Old coupons (from the oldest to the newest): AFfbG10, BGBFAFF2019, band10, BGVDay10%off, 0e7f33, BGband10, BGAFF10OFF, BG2KW01, BGSS10%SW, BG11SHOP, BGCuponation10, BG1813, BGWRIBAND10, 6GSGIT, BGfae0c6, BG51f436, BGc70579, BGbf11dd
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Here is price history (for all/most countries) for KINGWEAR KW01 Smart Watch.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).