Model: E8, External interface: Micro USB interface / 3.5mm audio interface (wired trainer interface), Item Name: E8 Radio Transmitter, Maximum output power: 22dbm, Charging system: Built-in USB 5V–1A linear lithium-ion battery charging system, Size: L*W*H=150x140x45mm, Weight: 260g (without battery), Brand Name: EMAX, Working frequency band: 2.4GHz (2400MHz-2483.5MHz), Working voltage: 3.7V-4.2V, Transmitting module: built-in 2.4GHz dual-frequency FPC antenna / 2.4GHz RF transmitting module, Channel: 8 channels / all channels can be configured, .
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.
Updated: 05-07-2025
Banggood
Warehouse in China.
Link: EMAX E8 2.4GHz 8CH RC Transmitter
$73.59 with coupon: BGMatt2022
Additional Banggood coupons:
1. First page
2. Second page
Price history and price alert
Here is price history (for all/most countries) for EMAX E8 2.4GHz 8CH RC Transmitter. The lowest price was: $71.99.
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)).