CCA KZ AZ09 Bluetooth 5.2 Module IEM Adapter Wireless Waterproof Ear Hook Extra Long Battery Life Bluetooth Cable for ​KZ ZS10 PRO/ZSN Pro X/ZSN PRO/ZSX/AS12/AS16/ZAX CRA/C12(C pin)

These work perfect with the KZ ZST iems. They are light and comfortable and stay even with head shaking. Sounds just as great as plugging in with an audio jack. The case is on the large size, definitely have to throw the case in a bag unless you don’t mind bulging pockets. The case also fits with the iems attached. Very happy with this purchase.

Had both. AZ09 and 15. 09. Best for smaller ears. 15 the latter. I love the stiffness in the 09. (If the latter isn’t first. I didn’t enjoy it. )Connection and mic quality seems to be the same. They hold iems with a strong arm and that i love.IF YOU HAVE SMALL EARS. AZ09.What ever iems u use. That’s fine. You can go jogging with these

Excellent sound and comfort!!! The design, clarity and quality were amazing!!!Only issue is after months of use the antennas seem to break and they become unusable at range, otherwise connectivity is amazing!!!Plus the casing likes to break in half when dropped and the buttons don't stay in place.

Only dislike is when changing songs using the button. The voice telling you that it changed is super compared to music, it's a loud beep super annoying. Other than that battery life is pretty good, connect to my galaxy with no problem

I've purchased 6 KZ IEMs, the bluetooth cable for "paragraph b" connectors, and a dozen wired cables previously. I love the IEMs, but got tired of the cables wearing out quickly. So I upgraded to KZ IEMs with the newer "paragraph c" connector, and got this Bluetooth charging case.From the beginning, the right battery/earhook would only occasionally charge. I had a lot on my plate, and assumed I was doing something wrong, because it worked maybe 1/10 times.I just put the left battery and IEM in naturally, and it always works. I checked both sets of contacts for the right battery, and came to regularly try taking it out and placing it back in as the manual says, as we'll as wiggling the right battery and IEM around in it's compartment, and pressing the battery down in the compartment to make sure the contacts connected. That didn't change the fact it would only charge 1/10 times. I tried only charging the earhooks with the case also charging via USB-C, and only charging both battery/earhooks at the same time, even though the instructions don't say you have to, and even imply you can charge them seperately. Those didn't work either.Today I finally put them in at a time when I had nothing else to do, and experienced the same issue as always, and thought I'd leave a review. If this charging case has issues, don't try to troubleshoot them yourself. Just return them in the return window.I should also mention that the bluetooth does well through a room. But the manual states you should have your phone on the same side as your earhook, I am assuming when the connected device you are playing from is in your pocket. Obviously when you're wearing both earhooks your device can't be on both sides of your body at the same time. I have found silly things block the bluetooth for the earhooks compared even to very old bluetooth headphones. Sometimes I lay with my arm over an ear, and it cuts out. One time I was just sitting around and it was cutting out, and in that one occasion, even holding the phone right up to one earhook didn't allow for stable audio. Just test them thoroughly while you can still return them.

This is a frustrating product. Especially when compared to something like the Shure TW2s.The build quality of the adapters themselves seem solid. The case feels pretty cheap, with the lid hinge in particular seeming like it could easily be damaged if dropped while open.The battery life seems on par with other Bluetooth adapters and the sound quality via AAC also seems sufficient, though support for AptX HD or LDAC is an obvious omission.Charging is nearly always a chore. Pogo pins once again prove their unreliability. I have maybe a 15% chance of both adapters shutting down and entering charge mode on the first try. Taking the adapter out of the charge case and cleaning the pins and pads seems only mildly effective. The only solution I've seen for this is to watch the bluetooth connection on whatever device the adapters are paired to and wait for the connection to break, which signals that both adapters are finally charging.The trick I've found to work around this flaw is to simply shake the closed charge case from side to side until the connection drops. The downside to this is that if you're carrying the adapters with you in a bag, they'll often lose their charge connection when jostled and reconnect to your phone when you're not expecting it. If this happens in a call, it's incredibly annoying.Where the true frustration really comes into play is in pretty much every aspect of software and firmware. They have no adjustment for the impedence of the attached IEMs and every sound and voice prompt is LOUD AS HELL. Using Linsoul KZ ZS10 Pros with a healthy 24ohms of impedence, the poorly enunciated English prompts jolt me every time. The "low battery" prompt begins at 30% and it's repeated so often (and so loud) that the adapaters immediately become unusuable until they're recharged.Switching between different devices is a catastrophe. The AZ09s will not switch devices when externally requested, something that every other bluetooth device I've used will do without complaint. They must be in pairing mode before they will even attempt to connect to something else, regardless of whether or not it's been paired before.This wouldn't be a deal breaker except for another of the software's flaws: there is no way to command the adapters to enter pairing mode. This is a baffling omission. The only way to get the adapters to go into pairing mode is to disconnect them from the device side. Forget to disconnect them from your PC before you left the room intending to connect them to your phone instead? You have no choice but to go back to your PC and explicitly disconnect them before they will allow your phone to request a connection. For anyone who switches their Bluetooth adapters between devices multiple times per day, this could easily be a deal-breaker.The adapters flash their too-bright blue LEDs every four seconds when in standard run mode. Why? I have absolutely no idea. They could have made that interval three times as long and it would still serve to signal that the adapters are powered on perfectly well.The voice prompts have the absolute bare minimum attempt at English. I refuse to believe that the designers couldn't fine a single person with a passable accent. It feels, like with many other aspects of the software/firmware, that they simply didn't care.With the newish Qualcomm SOC doing pretty much all the heavy lifting, the lack of any sort of polish software-side is a shameful waste.With no bundled app (which I'm sure would still be a minimum-effort affair anyway), there's no hope for firmware updates to address any these issues.The only aspect that redeems this product is the price. At $30, they're good enough. Unfortunately, they're also the best adapters available for the terrific range of 2-pin Chi-Fi IEMs currently on the market.

Excelentes, parea con iphone

It works but I cannot recommend.I am not sure if I got a bad unit but when I use these with my ear pieces I get a constant static/hum coming through as audio.It gets drowned out if you a playing audio at a mid to high volume but as soon as you have a bit of down time in your audio you are hit with this static.Note: I have no issues when I use my ear pieces wired.