Brand Xiaomi Mijia, Material 304 Stainless Steel + PP + Silicone + 316L stainless steel, Size 71.5x 65x 227.5mm, Cooling performance Less than 10℃ (6 hours), Weight 230g, Insulation efficiency More than 68℃ (6 hours), Capacity 480ml.
Basically copy coupon, view price history or create e-mail price alert. What is 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 and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($28.01): BGZPBC15
2. ($29.65): BGAFF10OFF
you should apply the coupon in your 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): BGD72903, BGXS126, 0e7f33, AFfbG10, BGTT10, bGhOnEy10, BGdragonBoat, BGCAMP01, bgshOOp10, BgoFErTaSchInA10, BgcLuBofErtA10
(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 Xiaomi Mijia 480mL Vacuum Thermos? There we go. The lowest price was: $19.99.
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)).