Working Current: 1.2mA, Signal to Noise Ration: ≤32dB, Harmonic Distortion: ≤10%, Max Gain: ≥ 40 ± 5dB, Size: 5*4cm/ 2”x 1.6”/ Length X Width, Max Out: 129 ± 3dB, Colour: Silver/ Light Blue.
Price history, coupons and price alert are available on this page. 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. There is one coupon available! Pretty cool, huh?
Link: Banggood product page
1. ($26.96): 2022ACTIESNL
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): ADMITAD2212, BG4efc25, BGHealth10D
(probably won’t work, but you can try them out)
Price history and price alert
Here is price history (for all/most countries) for Rechargeable Hearing Aids Amplifier. The lowest price was: $22.66.
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)).