KZ AZ09 Pro IEM Headphone Bluetooth Adapter, Bluetooth Module Upgrade Ear Hook Replacement Cable for ZS10Pro ZSNPro ZAS Zax, 0.75/0.78mm 2Pin Connector (Black, with Mic)

Let me just start off by saying that this thing rocks. It ticks all the right boxes for me. It has the comfort, discrete/small adapters hanging down, good battery life (I get 8 hrs) and the kicker; no cutouts or dropoffs! These things never have any problems staying connected even in a busy environment with lots of bluetooth devices around. Now the fit is a bit subjective to what IEM you buy, but the KZ ZS10 and this are a perfect match for comfort. I use spinfit CP100s and they are a decent pairing for this setup and there is a fair bit of isolation. I also have used the KZ/CRN ZEX PRO and they look excellent with these adapters, almost like they were made for each other. however the ZEX is a bit bigger and makes the hook around my ears arch up a bit more above my ear. It makes them a little less comfortable but isn't a deal breaker for me and with the ZS10 there is no issue. The case is a bit unwieldy, however I usually shove it in a bag or something and its not the end of the world for me. All around, if you're looking to make your IEMs TWS this is your best bet.

Great idea for wireless earbuds. I have used the AZ09 around the house and for traveling for around 5 or 6 weeks now Depending on what buds/items/drivers you buy, you can get whatever sound signature or price point you want. If this adapter ever breaks or can't be used, simply switch back to cable. It's a win-win! . But with that said, the wireless has it's downsides. Firstly, and most annoyingly is the noise floor. By design small driver's (ie IEMs and earbuds) are very sensitive, and need clean amplification to avoid the dreaded hissing. This ain't it chief. These adapters hiss quite noticeably during quiet passages, low-volume listening and in the 5 second gap when no audio is detected to shutting off the amplification circuit. As aside, the volume range is biased VERY loud. I've done 95% of my listening below 25% max volume, and have often run into 0% volume (completely muted) trying to notch them down just a little bit. It's very weird how they're designed to pump volume this loud and have such a high noise floor. Secondly is the annoying lights. If your buds are out of the case, but no audio is playing, they flash the little blue LEDs on the base every 2 seconds. This would be fine if they were subdued little indicators, but no; these are full power blue LEDs of death that light up dark rooms, blinding roommates and throwing blue reflections all over the walls and bedsheets and car interiors and even the ground. Why? Why do they feel the need to do this in such obnoxious manner? It like 2010s pc power switch that you'd tape over to stop you from going blind when you look at it. This issue is further exacerbated by the charging case. It does a similar thing with the battery indicator light every time you open it. Stupid bright green LEDs throw a light like kryptonite all around you everywhere. A simple 3 led array INSIDE the lid, with way less power would be much better. Speaking of the case - it's too big. It's about twice as thick and twice as wide as my Skullcandy set. You can't pocket the AZ09 in any comfortable fashion. I would sacrifice this bulk and extra battery for a smaller enclosure in a heartbeat. It's a bag-only kinda item, and it's a bit too inweidly to make it as grab and forget as say the airpods. The third and last negative I have to talk about is the lack of volume controls. Even cheap Skullcandy true wireless buds can do volume up and down. Given the shape and design of the AZ09 pro, there is plenty of space for a volume rocker along the backside, or on the flat spot where the flexible ear hook meets the plastic housing. Actually the last final quip I have to needle home is the odd quirk of how they are independent yet combined audio device in the Bluetooth system. It's only happened once or twice in the month or so that I've owned them; I'll pull one bud out of the case, put it in my ear, and when I get the second one out and situated it will not have any sound. Putting both back in the case and restarting fixes this issue. It's also noticeable sometimes when you adjust volume or play/pause suddenly, that the earbuds aren't 100% synced. One bud will lag just a little bit behind (40-100ms I'd guess). It's a little better with high performance mode (10-50ms). Having said all that, I still really like the AZ09 wireless adapter. For the price of the AZ09 and earbuds (KZ-ZS10 Pro), it's a heckuva lot more affordable than Galaxy buds or Airpods. They sound great, like 80-90% of the cable quality (highly dependant on BT source quality), and the batteries will last a very long time between charges. They blow my Skullcandy earbuds way outta the water in sound quality, last way longer, and also charges using USB C. I like the economics of the button placement, way more than clicking the driver in your ear. It's as intuitive as any earbud, but you don't change the fit in your ear and the click is tactile and has nice feedback. Kz makes all sorts of different iem drivers that are compatible, so the sound signature, colors and ear fit are all highly tailorable to your needs. I would recommend, but just know what drawbacks you're looking at before going into this system.

They came 2 weeks late. They only shipped after the estimated arrival date. The case is flimsy but easy to use ! No app I connected instantly they work well. Not loud with the iem I chose the linsole planar magnetic ones it's about good volume at max and I'm not one to listen loud. Will update after a few weeks Smaller then the Fiio ones I had and wore out . Few weeks in good battery high performance mode introduced crackle sounds sometimes infrequently but still annoying as much phones 60 cm away not very clear

I adore these things, I use them with my Pro X earbuds at work and they can just about last an entire 10 hour work day. When they don't the charge time is so short it doesn't matter. High performance mode is also very nice. I also happen to find the Asian woman speaking broken english to announce functions extremely charming. I love turning on my earbuds and hearing PAER ON and CONNECTATE and DISCONNECTATE.

This is a great product with a big achilles heel. The sound quality is great. The build quality and durability aren't the greatest but for the price I think it's fair. Battery life is pretty solid and meets what was promised on the listing. The BIG problem is the charging case. The connection between the earpieces and the charging case is super tiny and if it the charging pad on the earpiece or the metal prongs of the charging case are even a tiny bit dirty, the case will fall to properly connect and charge the earpieces and disconnect them from the device you have them paired too. You will need to do lots of removing and wiping down the pads/prongs until it finally is able to properly be received by the charger. I still recommend this adapter because it's a good value and the best option out there if you want to make you iem's wireless but I really hope they come out with an update that fixes this issue.