Transmission Distance 10m, Battery Capacity 120mAh, Frequency Response 20-20kHz, Charging Time (h) 1.5h, Impedance 32Ω, Standby Time (h) 200h, bluetooth Version V5.0, 3.7V, Working Time (h) 8h.
You can create price alert here, copy coupons and view price history. Let’s see what best price is ATM.
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. ($16.14): BGLOAC1
2. ($17.09): BG4BW25
3. ($17.99): 13f142
coupon code has to be applied in shop’s 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): BGBEZM, bgssaff9, AFfbG10, 502C6B, BGVDay10%off, EARSP11, BGAFF10OFF, BGTT10, bGhOnEy10, BGSS10%SW, bgshOOp10, BG11SHOP
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Price history and price alert
Here is price history (for all/most countries) for Baseus BA02 3.5mm Earphones Bluetooth 5.0 Adapter. The lowest price was: $10.99.
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)).