3.7V, Working Time (h) 8h, bluetooth Chip QCC3026, Charging Time (h) 2h, Transmission Distance 10m, 3.7V, Earphone: 60mAh*2, Standby Time (h) 180h, Frequency Response 20-20kHz, Battery Capacity Charging box: 600mAh, Impedance 32Ω, bluetooth Version V5.0, Microphone Yes.
Price history, coupons and price alert are available on this page. 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 coupon and price update (UTC):
Banggood
Banggood warehouse is located in Europe 
. I don’t really know if this price is reasonable, coz there’s no price history in my DB. There is one coupon right now! Check this out.
Link: Banggood product page
1. ($38.99): 13f142
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): BG20QCY, TTxBG10, aff7off, BGkonimbesinT3, BGT3, BG3CSUM, bgssaff9, AFfbG10, 502C6B, BGCITYADS2019, BGQCYT3CF, BGT3377, BGQCYT3, BGVDay10%off, EARSP11, BGTT10, bGhOnEy10, bgshOOp10, BG11SHOP, BGSK801, BG4BW25, BGLOAC1
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Price history and price alert
There is only one database record (it was for $29.99), so you can’t see price history chart.
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)).