Amazing device. It does exactly what it promises in a perfect way, very good sound quality and great range. RECOMMENDED

Very good, without noise and interference during simultaneous charging and operation, as I read in previous reviews! Excellent for its price!

Edit. It doesn't sync with the edifier w800bt, so I got it for free... Ultimately a bad purchase...

Very small, charges quickly, transmits sound well even through walls. Haven't tried it as a receiver yet. Works with battery without cables, and with a connected charger. The downside is that it doesn't have a volume button, so if you have the ability to adjust it from the source or headphones, then you're good, otherwise you're out of luck. The general downside of Bluetooth technology is the latency, half a second, which makes it unsuitable for some applications. For example, I got it to play the electric guitar wirelessly from the headphone output of my amplifier, but the latency makes it impossible to sync with what you're playing, so I connected it to the headphone output of my hifi to wirelessly listen to my vinyl records at inappropriate hours.

Flawless! My first experience with such a device. It does exactly what it says. It is small and discreet with good build quality. I bought it to connect a 7-year-old TV to a Bluetooth headset and I only use it in the TRANSMITTER mode. It has truly saved me. It connects instantly, never disconnects, has good range, and immediately recognizes the Bluetooth headset. (I use the EDIFIER W800BT headset). Maybe it could have a slightly longer battery life, and I would recommend using it without simultaneously charging it as there are interferences from the power. Truly better than what I expected for its price!