I would not be happy with my Meta Quest 3S without my KIWI design gear. That’s the truth. Through varied features, KIWI design’s add-ons have vastly improved the experience for me and my family. Whether it’s making the headset more comfortable to wear, boosting the battery life for longer play or wrapping the controllers in satisfyingly soft protective covers — do yourself a favor and go check the brand out if you own a Meta Quest.

To date, here’s everything I own: The H4 Halo Comfort Head Strap, K4 Boost Battery Strap, H4 Boost Battery Strap, G4 Pro Performance Controller Grips, the P4 Portable Carrying Case and now the K4 Duo AIO Audio Strap. Some I bought, some the brand sent me, but either way, I’d still have most of it.

The auxiliary gear fixes a lot of qualms I have with the Meta Quest design. For starters, the battery life on its own sucks. It’s abysmal. The KIWI design power straps essentially add a built-in power bank that connects to the USB-C port on the side of the headset, nearly doubling or tripling the battery life. The grips make the controllers more comfortable to hold, especially when your hands are sweaty. They also provide a more secure strap so you can ensure the controllers don’t go flying when you’re waving your arms around in front of you like a goon. The case makes it easy to stow the VR gear and bring it along out of the house.

But why so many headstrap options? Well, they all achieve something different, and the K4 Duo AIO Audio Strap is a great example. That also happens to be what we’re reviewing today, so grab a drink and a snack and let’s dive in.

What is the KIWI design K4 Duo AIO Audio Head Strap?

If you don’t own the Meta Quest 3 or 3S, the core system consists of the headset, the controllers, and a very uncomfortable headstrap. The strap is basic and uses velcro to tighten over your head. If anyone inexperienced, or anyone younger, is using the Meta Quest, it’s a pain in the ass to deal with and adjust. It’s even more frustrating when you’re passing the VR headset back and forth between different players.

The K4 Duo and most of KIWI design’s headstraps simply replace that basic strap, but with some pretty ingenious features.

Improved usability

For starters, once you clip the headpiece onto the headset and velcro the top strap, there’s a dial on the back that allows you to quickly and easily adjust the fit. Instead of fiddling with any velcro, you just put the VR headset on your head and tighten the dial — or loosen it before putting it on if it’s too tight. It’s quick, intuitive, and makes sharing the headset between players easier than ever, too.

Improved comfortability

The ergonomic rear headpiece and the strap together are also much more comfortable than the basic strap. I’m talking, you can wear the headset for hours and hours and still feel fine after. With the basic strap, my face starts to hurt, and the strap material makes my head itchy. It would also put a lot of pressure on your face, where my kids and I had deep, red marks on our cheeks for hours after use. That doesn’t happen with the KIWI design gear.

Improved battery life

Also, like some of the other KIWI headsets, the K4 Duo includes a 5,300mAh battery, which boosts battery life by two to three additional hours. Altogether, that gives you a total of about four or five hours of playtime. Plus, with a 45-watt PD charger, you can charge both the headset and the battery to full in about two and a half hours — this is called the DualFast charging system. I’m very thankful for this feature, as well. Otherwise, I’d be sitting around entertaining my kids while they wait for the headset to charge every few hours.

Immersive audio

Finally, and this is the top feature for the K4 Duo AIO Audio Strap, is a pair of integrated headphones that kind of rest over the top of your ears while you’re wearing the Meta Quest. They provide clearer, more immersive audio than the headset, which was already decent. I’m talking more bass, more sounds you can feel, and a hell of a lot more interesting audio experiences to go with the visuals.

How does the K4 Duo AIO Audio Strap work?

It simply replaces the stock head strap. It’s easy to swap out, too. 

You detach the basic strap from the plastic sidepieces — they snap off — and undo the velcro. Then, take it all off so you have just the headset by itself.

After unpacking the KIWI design set, you connect the ergonomic headrest to the strap, it just snaps into place. They come separately to make packaging easier. Then, you attach the new strap to the Meta Quest by sliding the velcro strap into the center attachment on the headset and snapping the side plastic pieces together. Finally, you plug the USB-C cable into the USB port on the side of the Meta VR headset. You can also unplug that USB at any time to preserve the battery, like when you have the Meta Quest chilling on the shelf.

When you put it all on, you adjust the strap using the dial, fit it to your head, and then swing the headphones down over your ears.

If you decide you don’t want to use the headphones, you don’t have to. My daughter, for example, doesn’t like them. You flick a switch to turn the headset audio back on and just slide the headphones up out of the way so your ears are free.

You’d expect all of that added hardware to boost the weight, but the K4 still manages to be fairly lightweight at 459 grams. It feels comfortable to use standing, sitting, and even lying down. As a matter of fact, I wouldn’t lie down to use the headset with the stock strap alone. But KIWI design’s head straps make that possible and reasonable to do. Add another point to the K4 Duo’s score.

How does it compare to the other KIWI design Meta Quest straps?

The battery straps, including the H4 Boost Halo, K4 Boost Battery Strap, SPC Battery Strap, and self-titled Battery Strap, add, as you might expect, additional battery life to the VR headset. They all include integrated batteries, like the K4 Duo.

They also come with the ergonomic headrest, which snaps onto the rear of the headpiece. As well as a vastly improved headstrap for the top. They all include the intuitive adjustable dials, too, albeit incorporated as a unique design for each strap.

Some have other features, as well. The H4 Boost, for instance, leverages a ventilated design for the facial piece, offering 360 degrees of airflow. Halo also takes the pressure off your face, whereas the Elite Head Straps put a little added pressure, but work well for more intense gaming sessions with a lot of movement and activity.

None of those options include the integrated headphones, however, and that’s where the K4 Duo AIO Audio Strap stands out.

Not just for gaming

It’s easy to forget that the Meta Quest and VR headsets aren’t designed exclusively for gaming. You can do a variety of things with them. You can watch movies and shows, browse the internet, utilize a virtual workstation, embark on unique virtual adventures, and so much more. But almost all of those experiences, especially the cinematic ones, rely on audio and video together. Of course, the Meta Quest 3 and 3S have the video and visuals down, but the K4 Duo AIO strap adds the much-needed immersive audio.

It’s to the point where I love watching movies on my Meta Quest 3S now. I pop some popcorn, kick back, and start the video on a pseudo 130-inch display right in front of my face, and it’s glorious. It also helps that the kids are usually in bed when I’m watching. The takeaway is that immersive audio truly changes how you experience and interact with the VR. It also works a treat when the Meta Quest is plugged into the PC or streaming from one.

One of the other benefits of the headphones is that the audio remains relatively confined to the person wearing the headset. Don’t get me wrong, they don’t block out the sound entirely, but when my kids are playing something like Beat Saber, I can hear everything they’re doing, like the headset is on my head — from another room. Now, all I hear is them singing along to the music. Again, it isolates that audio and helps keep it more localized for the player(s). This head strap came just in time, too, because I’m not sure how much longer I could handle hearing obnoxious cat purrs and meows when the kids are playing I Am Cat.

What’s the verdict, and the price?

Once again — and this is my opinion — KIWI design vastly improves the Meta Quest experience with this new headstrap. But really, it’s disingenuous to call it a strap; it’s a full-featured set at this point. It improves the comfort, boosts the battery life, nearly doubling it, makes the headset easier to adjust and swap around, and improves the audio. I’m not sure what else KIWI design could add at this point, but I’m sure they’ll think of something.

As for the cost, the KIWI design K4 Duo AIO Audio Strap is $140 at full price, which I admit, is a bit steep compared to the other straps — the Battery Strap is $60. But also, it’s on sale right now thanks to various retail events. If you compare the full price of the K4 Duo to the cost of a decent set of headphones or earbuds, which is essentially what you’re getting here, albeit proprietary, it makes sense. Not to mention, there’s a bunch more packed in there, too. Hello battery pack.

If your Meta Quest is sitting on a shelf collecting dust, you might want to sit this one out. But if it’s collecting dust because you don’t like wearing it, the K4 Duo is what you need. Or, even one of KIWI design’s other headstrap alternatives.

• Recommended Buy: Yes, all Meta Quest 3 and 3S owners.
• For Who: If you dislike the stock head strap, want something way more comfortable with extra battery life, and exceptional, immersive audio.
• Alternative: K4 Boost Battery Strap
• MSRP: $140