I got a classic Aeron and had no idea which color it is. Customer service helped me with this but you don't have to do that if you read this review.

There is a sticker at the bottom of the chair. If it says 3D01 it's Carbon, if it says 3D02, it's Lead. The two looks almost the same to me so I had no idea which to order. The carbon is more black and lead has this slight brown tint to it.

I got the H3 because I'm under 5"11", I would say it just barely fits me being 5'8". I'm adjusting the headrest to the full limit in height and well, it fits. It's just my OCD that wants to always have a little bit of room to play with.

The H3 comes with a smaller screw to attach to a Small Aeron. You can find out the size by touching the lip at the top of the chair. One bump is small, two medium, three is large. It also comes with two extra plastic caps which can damage if you are not careful when removing them to adjust the tension. I was not careful and it nicked a little but smoothing out with my finger sort of healed it.

I had to adjust the tension to make it not flop around if it rest my head with a reasonable push.

Overall, it's absolutely required to have a head rest for me if you want to sit on this thing for the entire day. Even right now, I'm resting my head on it so it takes a bit of pressure away from your neck. Overall, I'm happy with this purchase as it just looks complete now.

I've had my Aeron for well over a decade now. Still just as good as new. Happened to come across this headrest, and thought it's $$$. Ended up getting a home office stipend due to Covid-19 and thought I might give it a try.
It's very easy to install and quite nice to use. The materials are top notch and appear to be the same pellical that the Aeron uses, which has held up beyond expectations.
The only 2 (minor) issues I have is:
1) it's quite expensive for a clamp on headrest.
2) it's not quite as adjustable as I'd like, specifically forward and back.

It's also not "solid" in that even after tightening the adjuster bolts, it's still pretty easy to "move" by just grabbing it and pushing.

Instructions indicate that that's intentional, and it's not too bad. I'll have to use it more to see how that works out.

In the end, if you're going to upgrade your Aeron, I'd suggest Urethane castors first, and this headrest second.

So happy to have found this product. After working from home for months, my neck has been giving me issues in my Herman Miller chair. Adding the headrest helps support my head and neck better during long work days. Really recommend this for the perfect companion to your Aeron. Really completes the comfort and investment for me!

Installed in less than five minutes. Looks EXACTLY like the original materials/finishes on my 10-year-old chair. And is as comfortable as the chair is too! Perfect!