The basic nature of the EFM Athos True Wireless headphones extends to pairing, which uses the standard Bluetooth route of powering up when they're removed from the case, at which point you've got to then go hunting for them in your phone's Bluetooth menu. Pairing over Bluetooth was quick and painless, and if you're not a fan of headphones that want a companion app as well, they could have a lot of appeal.
The EFM Athos True Wireless headphones aren't all that expensive, so my expectations weren't super-high in terms of audio quality. It turns out that this is exactly the attitude you should have with the EFM Athos True Wireless headphones, which deliver a mostly flat music experience with little in the way of nuance.
Listening to Freddie Mercury's rising vocals on "Barcelona" robbed that song of an awful lot of its stadium-style presence, especially in the soaring vocal parts. Not to a level where I didn't want to continue listening, but certainly below the grade that you can get with more pricey wireless headphones.

Switching over to The Beastie Boys "Nonstop Disco Powerpack" gave similar results, with the underlying bass line appearing a little more flat than I'd really like. Again, this is entirely in line with the relatively low price of the EFM Athos True Wireless headphones.
Where the EFM Athos True Wireless headphones did work better was as a basic set of podcast listening headphones because typically there you can forgive more ordinary audio quality more easily. If you're happy with basic and low audio bitrates offered by some music streaming services, the EFM Athos True Wireless headphones could be entirely fine for your needs.
The oval shape of the EFM Athos True Wireless headphones doesn't make them hook all that solidly into your ears, which also means they move around a little when you're walking with them. I didn't have them fall out while jogging, but they did feel more loose than many other pairs I've tested, and that was with the medium tips inserted. Of course, your fit conditions may vary.
The EFM Athos True Wireless headphones go down the very usual route of providing touch-based controls for simple functions such as play/pause, call answering or invoking your virtual assistant of choice. At least, in theory that's the case, but like so many of their ilk, actually doing anything that involves more than one tap is fraught with peril. Pausing and playing off a single tap is fine, but about half the time, the double tap that should skip a track instead decided to fire up the assistant on my paired phone.
The small bud nature of the EFM Athos True Wireless headphones also doesn't lend itself brilliantly to phone calls. While there's a lot of variance in any mobile call, people I spoke to while on the EFM Athos True Wireless headphones said I often appeared rather soft and distant. Calls could be made, but I've certainly had better experiences with other true wireless buds in this respect.