SOLOVE N2-S Winter Hand Warmer (Banggood, Aliexpress: Size 98x 66x 33.8mm, Output current DC 5V-21A, Battery 4000mAh / 3.7 14.8 Wh, Night light power 0.5W, Rated capacity 2960mAh, Input current DC 5V-18A, Heating power 8-10W, Fever time 3.5-4h, Weight 130g (the best price with coupon)).
You can create price alert here, copy coupons and view price history. You probably want to know what is the 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 price update (UTC time):
Banggood
Banggood warehouse is located in China. I am tired of searching coupons, but I found one for you…
Link: Banggood product page
1. ($19.65): BGODFN1
this code has to be applied in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/feV
Old coupons (from the oldest to the newest): BGD65413, AFfbG10, BGN2SPL, 502C6B, BGD11NB, BGBFAFF2019, BGH5P, BGCITYADS2019, BGOC148, 0e7f33, BGCAMP01, BG10OFFAFF1, BG4d9120
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – SOLOVE N2-S Winter Hand Warmer [EU] ($-3)
Price history and price alert
Price history (for all/most countries) for SOLOVE N2-S Winter Hand Warmer is here. The lowest price was: $13.69.
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)).