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)

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

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.

Update: I decided to replace the unit. This replacement is working great and I am enjoying using my KZ Z10 Pro with the bluetooth. While walking at the park I noticed the sound dropping on the left ear for a split second, and again the next day it happened again. So far it's very infrequent and doesn't bother me, not what caused it but at those times I was in motion with my phone in my pocket. Battery life has been good, i haven't ran them to low yet, the longest I used them in one use was like 2hrs. The call quality could be better, sounded a little choppy for what I was hearing and I'm not sure how I sounded on the other end. Comfort wise, it felt good, it's not heavy on the ears and it conforms well. When I use my IEMs at work, the dangling wire tends to bother me a bit with the pull in my ear hooks but with these units, it just sits comfortably on my ears. Overall I'm satisfied using my IEMs for more than just work now. I don't plan on using this Bluetooth for calls as much as I do for music and it does well the Z10 pros sound like they are wired. Original review: My left ear hook unit seems to not charge, I lift it out of the case, it turns on and then turns off by the time I securely place it over my ear. Its looks like it's charging when I place it in so i am not sure what's happening. The right unit is working fine and sounds great but I haven't even had a chance to use both together except for the initial setup and one other time after. I've tried resetting them and resyncing, making sure it charged over night, and placing it correctly without moving the charging case. Nothing seems to work and the left unit just turns on and off. One star for comfort because I only worn a single unit.

You are sacrificing a few comfort features with these as an upgrade to your wired earbuds. You dont get ANC or audio pass-through. What you do get is the ability to upgrade exceptional wired KZ earbuds that are insanely comfortable (better than airpods or Sony XM5 buds) and listen to music at a better sound quality than what you can get with other wireless buds on the market. These are so insanely comfortable it's remarkable. They feel so secure I'll start wearing them through my sprinting regiment

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.