bluetooth protocol HSP, Color Black, Material ABS, bluetooth distance 10M, Battery 300mAh, White, A2DP, Speaker impedance 32Ω, Weight 4g*2, Model X9, bluetooth version 5.0, Music/Call Time About 3 hours, Speaker sensitivity 105±3dB, HFP, Frequency Range 20-20KHz, AVRCP, Charging time Earphone: 1.5 hours, Charging Case: 2 hours, Waterproof level IPX5.
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 China. There is one great coupon!
Link: Banggood product page
1. ($26.49): BGAlerabatKL
apply it 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): BGLEX9, BGLOAC1, 13f142, BG906a85, BGa0b145, BGBuscape01, BG651551, BGBRPL2, BGHOTSHOP15, BG53e9c8
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Check out price history chart (for all/most countries) for Lenovo X9 Bluetooth 5.0 Earphones. The lowest price was: $15.55.
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)).