CCA KZ AZ09 PRO Bluetooth 5.2 Module IEM Bluetooth Adapter Waterproof Ear Hook Extra Long Battery Life Cable for ​KZ ZS10 PRO/ZSN Pro X/ZSN PRO/ZEX PRO/AS16 PRO/Zax/DQ6 Polaris/C12/CRA PRO(C pin)

I use these on the daily at my desk and for calls. Such a nice alternative to using over the ear headphones.The battery typically lasts around 8-10hrs, but they never really die if you throw them in the charging case when you're not using them for a moment.They fit pretty well for the average person, but if you wear glasses they may get a bit loose over time.My only real gripes are with the microphone and device pairing.The microphone is decent for calls, but since it's facing away from your mouth it can be a little quiet.When switching devices you have to turn off the Bluetooth for what you're disconnecting from and select the AZ09 on what you're switching to. So it's a little annoying.After a few months one of my earhooks stopped working. I contacted the seller and they sent over a new pair. I really appreciate the warranty. Very nice and communicative seller.

So, the charging box is a little jank, feels a bit plasticky and large, and doesn't always register that the earbuds are changing and should be unpaired so I usually just do that manually.Other than that, I absolutely adore this product.As a musician, I've used wired KZ10 in-ears for years for performance. Being able to use a set of KZ10s as standard, walking around earbuds has been such a huge step up from regular Bluetooth earbuds. The sound quality is far and away better than my Klipsch T5 ANC buds that are about twice the overall cost. These also sound much better than any of my other wireless earbud sets from Anker and are also about 2 to 3 times louder.The reasoning is pretty simple: since this is an add-on Bluetooth module that goes around the ears, the actual earbud (the KZ10 IEMs) is only speakers. Normal consumer wireless earbuds have to fit speakers, batteries, buttons/sensors, microphones, and the Bluetooth radio in to the same amount of space. So yeah, since these buds put all the electronics in the over-ear hook, the "bud" is allowed to focus solely on speakers and speaker quality.I found these to be super comfy and well sealed: they're musical performance earbuds, so that makes sense. They stay in the ears well and have excellent battery life/bluetooth connection quality. And the sound quality is impeccable: far better clarify than normal buds, excellent bass, a good amount of separation between lows, highs, and mids. What can I say, they sound much better than normal buds.I had no idea this product existed but I'm so glad I found it: absolute LEAP forward for sound quality with my EDC buds. Try it, you won't regret it.

Sound quality is soo much better with the cable and the quality is low

I've had my KZ ZS10 ProX IEM's for about one month and absolutely love them. Up until now, I have always used them wired to my Presonus audio interface connected to my PC. I wanted to try a Bluetooth solution so I ordered these and the cheaper, non-pro version. My phone is a Samsung Galaxy Note 20 with the aptX codec available. So I can take advantage of this AZ09 Pro version having that feature. I wanted to see if it's worth the extra cost to have that option and others like the all silicone ear hooks and higher capacity batteries. These also pair seamlessly with my Gaming PC. I've tested the "Performance mode" which is activated by triple tapping the button on the right ear. It eliminates virtually all lag. I watched a few YouTube vids and the audio sync is nearly perfect. Nothing to complain about. I'd even be comfortable recommending these for PC gaming. Aside from hard-core competitive FPS games, I think most people would really enjoy the extra sound stage and immersion factor. These would pair really well with a gaming laptop for a super compact audio solution. Just keep in mind the microphone on these is for calls only. I haven't been able to select it as a mic device on Windows 11.Fit and comfort:The verdict simply put is, yes. The much thinner silicone vs hard clear plastic ear hooks on the non-pro version are thinner, lighter and softer making them more comfortable. Build quality is great on both versions but these are just noticeably better. They attach to the IEMs snug but not overly tight.Sound Quality:While going wired will always sound the best, both these and the AZ09 non-pro versions sound pretty decent. Noticeably better then many much more expensive BT earbuds. The sound stage shrinks via Bluetooth. There is really nothing you can do about that. The AptX codec can help a little with this but what it really does is lower the constant low level noise you will always experience going BT. Not only does this more advanced codec eliminate some low level noise you get from going wireless, it digitally expands the sound stage back out just a little. Don't expect the AptX codec to work miracles. The drop off from wired to BT is very apparent regardless of the codec used. I went back and forth between the two through my Presonus Audio interface for my wired test and through its BT functionality in a controlled environment. I would say you get roughly 75-80% the quality of wired. The AAC codec on some IPhone's and other portable BT capable devices is even more so of a drop off in overall sound quaity. If I am close enough to my desk to hook back up wired, I take the 60 seconds and do so no question. Its worth it. But around the house or on the go this BT solution even with the sound degradation, is well worth the portability.Features:KZ-AZ09 Pro over non-Pro--AptX codec-Approximately 20% longer battery life-Silicone coated vs hard plastic behind the earIn conclusion, with the current 20% off price I think the Pros are worth the extra cost. Make sure your device has the AptX codec though. If it doesn't just stick with the non-Pro version as the cost difference wouldn't really be worth the upgrade without it. The mic not being restricted to only calls so I could use it to chat on my PC would have been a really nice feature. Also there are no volume controls on the modules themselves. You must use your device to control it. And as much as like these overall, the drop off in sound stage is pretty significant. As stated above, I do feel there is a step up over more expensive name brand earbuds. So final rating is 4 of 5 stars. The stay connected, are lightweight and comfortable.I do recommend giving them try if you like how your IEM's fit and feel. Just do not expect the same sound quality as being wired up.