For the price I would say they are good. First of all I have to say that they have a longer battery life and they were amazing compared to other headphones. Like everything it's not perfect but what they say and what the product delivers are two different things. The 5.0 sound is low compared to other brands, but it is clear and loud enough. Soundproofing explicitly instead of external noise cancellation. As another person said, the control process is not what it should be and I have tried many times to use what the company says. There's no up and down volume control here, and it's easy to "accidentally" cause the headphones to pause, turn off, or whatever. The fit isn't the same as other brands, but I didn't fall out while running, they fell out over time, which is very annoying. I use the little ones like others and they feel like they slipped out of my ear canal. Pairing wasn't easy for me as I paired the F9 with my phone but it only paired one earbud so I started from scratch and the earphone designation is F9L and F9R. I like the fact that I can choose to have one in and the other in a suitcase and it won't put me off. What is primary and secondary seems to me that this changes when the last pair becomes primary for some reason when both are running at the same time. Yes there were some disappointments and I could have returned the headset but for my use and the like I definitely like it for the price I got it for. If there was more then yes I would send it back. I gave 3 stars yes but for under $20. I would say this is a good buy.
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