KZ AZ09 Bluetooth 5.4 Module Wireless Waterproof Ear Hook Extra Long Battery Life Bluetooth Cable for ​KZ ZST/ZSTX/ZS10/AS06/AS10/BA10/ZSR/ES4 (B pin)

Another great purchase to write about! I work around our property every weekend and being a music lover I always have ear buds in so I can listen to tunes while I work. The problem is apparently my ears are misshapen in some way that makes every ear bud I've tried not seat correctly so the buds fall out of my ear. Anyone who constantly has to readjust or push their earbuds in can feel me on that point. I wanted a quality ear bud that fit securely and wouldn't come loose as I worked - and this product didn't disappoint. I will say that being Chinese made, it has some funny quirks - it sounds like the lady announcing that the device has connected says "Connectate" instead of "Connected". I don't really care about that though - all I care is that the sound is good quality and the buds stay firmly in my ear. This product did both very well and I'm loving not having to take my buds out and reseat them every 5 mins. I'm using a after product foam type ear piece - you can squish it down tight, put it in your ear, and it will expand to fit perfectly. Battery life has been great for the time I've had these (about 6 months). I'll work around our 7 acre property for 6-7 hours without having to charge and it still has juice left if I forget to charge them. This also has an option to be used as a corded ear bud as well, which I did find useful since I travel a lot and use headphones with a plug while flying to watch movies or listen to music. Now I have the best of both worlds. From a cost/value perspective you can't beat the price and they do seem to be of good quality. I would recommend this to anyone looking for a versatile set of music buds, that stay put in your ear and block out unwanted noise, keep their charge for 7+ hours, and are easy to pair to your phone/tablet or computer. I'd definitely buy them again.

I’ve been using the KZ AZ09 adapters with my Melody IEMs for about five months now, and they’ve quickly become my go-to setup for work and daily use. The bass hits hard, the clarity is excellent, and they get plenty loud without distortion. No compromises in sound quality compared to wired use—they drive my IEMs effortlessly. Pairing is instant, and I’ve had zero connection drops. I’ll leave my phone in my truck and walk around a job site or warehouse, still connected clearly over 100 yards away. Battery life is phenomenal—I get multiple full workdays without needing a recharge. The charging case is simple and solid. It announces when you’re connected, and it’s never let me down. The touch controls are responsive and cover all the basics: play, pause, skip, volume. I’ve made calls with them too, and the mic quality is surprisingly crisp—no one’s ever complained. They’re also ridiculously comfortable and secure. I forget I’m wearing them most days, even after hours of moving around. The build quality is legit—they’re sturdy, not flimsy, and they’ve survived multiple drops without a hiccup. At this price, the AZ09s are a no-brainer. If you’ve got a favorite pair of IEMs and want to go wireless without losing sound quality or reliability, these are absolutely worth their weight in gold. ⸻ ✅ Pros: • Fantastic bass and clarity • Incredible Bluetooth range (100+ yards) • Long battery life (multi-day use) • Reliable, quick pairing • Comfortable and secure all-day wear • Durable build—survives drops ❌ Cons: • None that I’ve encountered

I still have the set and charging case and it still works fine. Best pair of earphones I've ever had before. Sound is great as long as they are fitted in your ear correctly. I use them when I mow the yard mainly, that's how good they are. Though they will slip loose and let sound in as I get sweat on my head. They don't last all day on a single charge either but they can go for a couple of hours before needing to be put back in the charge case if your using the BT mode. I also have the wires so I don't have to use the Bluetooth/Battery adapters unless I want to. The units pair with any Bluetooth device, so I can use them with my phone, or either of my computers easily. I got the earphones with wires for $20 and the BT and battery for $30 so a little over 50 dollars for all the components. Considering how expensive name brand versions of these things are I feel like these were priced fairly and was a good deal. Thanks

I just ordered a second one. Sound quality for Bluetooth is INCREDIBLE!!! I’ve been using with the castor pro bass edition. At 1st I was iffy, but there was a slight learning curve for me. A hidden feature boost volume and performance by pressing the left button 3x. If you own an iPhone as I do, don’t mess with buying the pro version of the az09, because the difference isn’t worth the extra $20.00. The regular version is AMAZING!!! I’ve been using it nonstop with no issues AT All. I own the AirPod pro gen 2 and listening to music with this is 3x better than those. The battery life is good for me. I think the longest I’ve used them straight is about 4hr with no problem. Had them for about 3 weeks at this point and only charged the case twice so far. They seem to have a nice build quality, no issues in that area either. For the price $ in my honest opinion I don’t think you’ll find any better bt adapters for iem’s like this. I bought my first pair for $30.00 then noticed them on sale for $24.00 and said yep, I’ll order a back up pair just in case. All boxes check for me though sound quality awesome, noise floor almost non existent. Good battery life. Nice range, about 30 feet. Good build quality 👍🏻 and the mic works good on phone calls as well.

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.

Okay so I'm returning this. Not only is it randomly disconnecting now, the "coonickteed" (Connected) and "deezcunecteed" (Disconnected) notifications in ear are EXTREMELY loud and infuriating. I really wanted to make these work because I like the format, but I just can't take it anymore. I'll get a Bluetooth headphone adapter or something. Anything is better than this cheap overpriced piece of Chinese crap. I've added a video with audio (it doesn't accuratly depict how loud it is when they're in your ear) so you can understand what I'm talking about. It was funny at first when it was only happening in the case before I put them on my ears, however when they are on and you are listening to high Fidelity music or something, and they randomly disconnect and you get an ear piercing notification that they have been "disconnected" shortly followed by a "connected", it gets old FAST. Anyways, they're going back. OLD: Functionally they work very well. The audio quality is fantastic for Bluetooth and they are very comfortable. The only complaint I have is the voice that says when it's connected, in pairing mode, etc. It's like they looked for the worst, most unclear, terribly challenged foreign accent they could find, and then compressed the audio to a point it sounds like it was recorded over a phone line in 1876. It just makes it feel like I should have bought it at the dollar store.

Works perfectly. It's comfy and has a good grip on my ear, no chance of it falling out. Battery lasts a long time. Charging case is nice too. My only problem with it is the flashing light when pairing is a bit too bright. I was worried about choppy/poor audio, but it turns out it was a problem with my computer's bluetooth usb dongle. It works fine when paired to my phone.

Bluetooth connection is flawless and battery life is exceptional. Mine get used 5 nights a week at work and I believe my 3rd year now. Comfortable to wear with the IEM.

Just what I was looking for, Quality seems good, as is the sound,

Bom

Overall a good product, but the one thing bugging me is when I have the volume low and on AAC codec which is the highest quality on android it will cut out quieter frequencies. Otherwise, it works well with my KZ ZSN PRO X's with huge range, sound quality that sounds the same as wired except for the issue I mentioned which happens below half volume.