Play Time Music: 4h, Waterproof IPX4, Battery Earbuds 40mAh, Model AA-UM4 Pro, Charging Box 300mAh, Talking: 3.5h, Input DC5V-1A, Brand AirAux, Charging Port Type-C.
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 and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($14.99): BGfc878c
2. ($22.35): BGBuscape01
put item in your cart and apply coupon code there after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BGSK611, BGUG661, BG7833fb, 13f142, BG242167, BG4b26c4, BG4189b7, BGa0b145, BGa5e36d, BG35f901, BGc256ec, BG128560, 6GSGIT, BG53e9c8
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – AirAux AA-UM4 Pro TWS Earbuds [EU] ($-3)
Price history and price alert
Do you need price history chart (for all/most countries) for AirAux AA-UM4 Pro TWS Earbuds? There we go. The lowest price was: $13.99.
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)).