I would say that it's the best thing I actually got for my headset it doesn't overheat plus I can play with her very long time without it going crazy from the heat

Exactly as advertised. Keeps my lenses from fogging up, and creates a small airflow over the front of my face when doing extraneous activity in VR.
This is useful if you work out in VR or play any game on a competitive level. There is only one USB-A port at the front of the headset, so it is not compatible with other face attachments such as face tracking, eye tracking attachments, and whatnot. Fits seamlessly into the headset and clicks into place.
Does not fix sweat over eyes; Need other headset attachments/modifications for that. Does keep face from burning up or eyes from getting uncomfortably warm.

It was as described in the description

-edit 2-
They shipped me a new one incredibly fast, and it DID have a longer USB cable. It was still not as long as in the photos though, but it was actually possible to install it this time. The USB cable plugged in fine, and when you go to set it into the slot it comes out ever so slightly (so slight that it won't pop-out, practically fully in) I used a small tool to push it in further once the fans were in place, but not pushed down. I am moving my review to 5 stars because of the quick response time and fast replacement of the product, even if it still is ever-so-slightly flawed in one aspect. Otherwise it is a great product and really helps keep my face cool inside that helm. So I recommend it, and don't hesitate to contact support if the cable is too short!

-edit-
I bumped it from 2 stars to 4 stars for right now because I contacted KIWI customer service to tell them about the short USB cable. They were super quick to respond, and asked for photos for a better understanding. I sent, they apologized and asked for my address to send me a new one free of charge. So A+ great customer service. I'll edit again when I get the new one in.

-Original Review-
The photos on the box and on the instruction manual both show the USB at a length that would be acceptable but the actual product has a USB length that makes it nearly impossible to plug in. The fans snap down into the Index, and that makes it very difficult to plug the USB in (can't slide the device in). Even if you did manage to plug it in it would barely be making contact with the USB pins. So yea, you might get power, but I bet it would fall out during intense VR gaming. I saw other reviews mentioning this and I was prepared. I had a small 1.5 inch USB extender that did the trick, but it meant their cable bunched up a bit awkwardly, it did work in the end though. I do think there must be a defective batch out there with Cables that are too short. I'm going to contact customer service.

Let me preface by saying I love it, this thing is great but it ain't cheap. For it being so expensive (because KIWI knows it basically has the only version that is this compact and actually does a good job), the build quality is bad. I gave it 4 stars because it works. It does it's job. But the cheap plastic just ain't it. Also, the fans went from barely any noise to now sounding like meat grinders. That may be partially my fault as I dance in VR and occasionally smack my head here and there. I tried replacing through Amazon and they told me to go through KIWI. Still awaiting a response after 2 weeks of sending a message to get a replacement. My initial complaint was one of the fans stopped working, but I literally gave the thing a good smack with my hand and that fan has been working again ever since lol. Sometimes smacking something does make it work lol. My main gripe now is how loud the unit got over time. To anyone that buys this, it really is great. But please, IF THEY OFFER THE WARRANTY, PLEASE DO YOURSELF A FAVOR AND BUY THE WARRANTY. I thought I'd be fine which was dumb of me because I always buy warranties for products. I won't make that mistake again. Warranty means I can go through Amazon or a respective party. Dealing with KIWI so far hasn't gotten me very far after Amazon sent me their information. I'll be honest, I'm probably going to end up buying another unit once this one completely fails and next time buying the added warranty for it because this thing really is a life saver for my eyes in VR.

Overall it's solid. You feel the air come through the headset which for me was a much needed relief. My contacts would dry up inside the headset due to heat but with the fan, it keeps air coming in and reminds my eyes to blink. Without it, I forget to blink a lot and dry out my contacts to where I can't see anything. This really is a must have. I know my review is kinda rough but again it's partially my fault and I know this. But if the build quality was better, it would be 5 stars with no complaints.