For $15, you could do worse.
These headphones come with a 3.5mm cable, charging cable (USB-micro), and that's it. The right cup has all the ports and buttons, three buttons and two ports. USB is at the back, then the 3.5mm, then the three buttons for bluetooth control. The design is simple, matte black with a glossy black ONN logo on either cup. They look plain and unassuming and boring, which is not a bad thing.
The feel of these headphones is uncomfortable. I usually hate on-ear headphones but I liked the comfort of the Jlabs studio, these are the opposite. The pads are stiff, the clam isn't horrible, but the top headband is bare plastic and hurts. These will hurt your ears after about 20 minutes, but I'll soldier on for this review.
Bluetooth here is SBC/AAC as usual in this price range, no APTx or LDAC. It keeps connection well even at 20 ft in my kitchen. Nothing special here. I am testing these headphones as such: PC > DX7s >RCA> 5.0 bluetooth Transmitter > Headphones.
The sound though, it's not bad for $15. I am comparing these against a no brand/gas station pair of headphones at the moment and I would choose ONN over gas station. These are heavily V-shaped sounding. The bass is the biggest focus on these cans, the highs are ok but not as strong as the bass. The highs sound mostly clear but EDM bass shows that the bass is distorted and sustained, not a POP but more of a long roll off. These are not the headphones for ROCK or METAL but EDM seems to be the focus. Listening to "Bitches Brew" by Miles Davis I can tell what instruments are playing, but lacks definition. I searched around my JAZZ collection to find tracks where I could hear brushes over sticks, I couldn't tell with these headphones. POP tracks with bass distortion sound odd, the roll off messes with my hearing (I'm spoiled by so many good headphones, sorry!).
Now for the 3.5mm testing from my SP200 THX amp. The extra power cleans up alot of the sound, or maybe that's the magic of THX? The bass response sounds better, still not a pop as I prefer. ROCK and METAL still don't sound as they should. The distortion on the guitar really overpowers alot of the sound. The mid range is still recessed and it sounds pushed even further back. The highs present a bit better, stronger definitely, but still not as clear as I would like in a headphone.
I do have to comment on one thing, these can handle the power. I was expecting to put these at full power, high gain, max volume on my SP200 and blow a driver. After 10 minutes of "too loud for any ear" volume, they still sound the same and didn't blow.
In short: Too much bass with too much bass distortion for a majority of uses. Given that these are $15 wireless headphones with 14 hours of battery, you could do worse. If you have no choice, these will get the job done and make noise for your ears. But I would wait and double your money for some other options. These should be your last resort.
(Disclaimer: I bought these. ONN has no idea I bought them, gave me no incentive for this review, and likely wasn't expecting any reviews. I took the included photo from google images because my camera is shit.)