Aeron Chair’s Size and Customization

Aeron Chair’s Size and Customization

The Aeron Chairs sold on the website are all fully loaded.
They come with full features, with FULL ergonomic functions, including recline tilt limiter, seat angle adjustment, forward tilt and FULLY adjustable arms.

The following options or upgrades might be available

  • Posture fit SL back support.
  • Hard or standard hard castors.
  • Add on a fully adjustable headrest from Engineered one(USA) or Atlas.

We do not order the basic models as they don’t have ergonomic features.
The most commonly ordered upgrades are the hard castors and headrest addons.

The information below is for the Remastered Aerons only. The classic version may have slight differences and has been discontinued.


You will first have to select the correct size.
Below is the size chart for Remastered Aerons.

Here are the links to the chairs:

Size A

Size B

Size C

Getting the suitable size base on the chart will be the most accurate, even more than testing yourself.

If the given weight and height have two possible sizes, users are encouraged to read the chart and decide which size it’s closer to.

Do note that if the chair is too big, the user will lose the dexterity to tilt the chair with better manoeuvrability. The user does not have the weight and height to angulate and pivot the tilting mechanism.

Posturefit SL Backrest Support

The Posturefit SL has two pads that support the sacrum and lumbar region, and its depth can be adjusted to fit the spine curve.

There are two types of back support for the Aeron chair, Lumbar Pad and Posturefit SL.
We only carry the more premium Posturefit SL for its preferred support.

The main advantage of the Posturefit SL over the Lumbar Pad is that the position is fixed, does not slide away from the user’s movement, and has better support closer to the thoracic area.

Herman Miller Remastered Aeron Back
Posturefit SL

Hard or BB Carpet Casters

Casters are the wheels of the chairs.

Standard BB casters are for carpets, they are tough wheels with no additional coating. It can be found here: Herman Miller Standard Carpet Casters

Hard floor casters have a softer polyurethane coating on the wheels, increasing the traction to keep the chair from gliding away easily. The coating also reduces noises during rolling and reduces the chance of scratching the hard floor.

There are two versions of hard casters.

  1. Original from Herman Miller
  2. German-made Premium Hard Casters

Unfortunately, the original wheels are the most common cause of failure. The wheels can start to scratch or stain the floor as they harden over time or break.

To deal with this, we have worked with the best industrial caster producer in the world, who specialise in producing casters for high-stressing environments. As a result, we have co-invented the German Made Aeron Casters that use a specially requested material, which is much more lasting, less noisy, has smart braking features and is less likely to scratch the floor.

As the special material is specially sourced and requested by us from another science faculty, these casters can’t be found anywhere else in the world and can ONLY be found on our website. The new casters last at least 5 times longer than the originals, and there are no broken casters to date since their debut almost 10 years ago.

The 100% German-made casters come from the same OEM factory as the original and can also be used on carpet flooring. They come with rollaway resistance and a subtle braking system that keeps your chair from rolling too far away when unused. They also have the latest noiseless roll technology, which significantly reduces the amount of sound from vibration when rolling.

Below are photos of the Original hard casters that break within three years.

Herman miller casters shedding
Herman miller casters breaking apart

Do note that if you choose the Original hard casters, they deteriorate within five years due to poor compatibility with the flooring. They will be replaced with standard BB casters.


There are several options for the headrest. Below are the top 3 options available in the market.
The headrest will be useful for leaning back for napping or resting the head in a reclined position.

Engineered One Aeron Headrest.

Engineered One made the most successful headrest for Aeron chairs since the Classic Aeron series more than 15 years ago.

It was recognised as the missing piece that gives the Aeron chair additional support to the neck. They are durable, fully adjustable and provide excellent support.

Key advantages:

  • Patented design for full adjustment with better manoeuvrability. Height, Depth & Tilt Control
  • Angles can be tilted to any degree.
  • Synchronized angling when the user tilts.
  • Flexibility in extending to both height and depth.
  • Able to lock positions for most joints. (Many other makers have a problem with locking in the depth and getting out of position).
  • Mesh design – No entrapment of body heat causing discomfort.
  • Better flexibility on the mesh to facilitate contouring.
  • Very good durability.

There are two versions.

  1. HR03
  2. HR04

HR04 is 20% larger and can be adjusted taller


HR03 for remastered Aerons


HR04 for remastered Aerons
HR04 versus HR03

We do have headrests for the classic Aerons as well.

Reviews: Customer Reviews: VendorGear Headrest for Herman Miller Aeron Chair

The main advantage of the Engineered Nne headrest is its adjustability and its breathable material. It empties every gap from your entire spine up to your neck, developing the perfect support.

To support the head well, the right place to support is the neck. Else if the headrest pushes the head, it will lead to the forward head posture

As it’s fully adjustable, you can tune the right angle to fit the position of your neck, as well as how much support is necessary.

It fits so snugly that you can’t move much out of your correct posture.
We highly recommend this upgrade above all the other upgrades.

Another thing is the tension can be adjusted by tightening the screw.
Engineer now headrest 2

Engineer now headrest 3

Here are their links:

HR03 Engineered Now Aeron Headrest

HR04 Engineered Now Aeron Headrest

Ergonomic Aeron Headrest (OEM)

An OEM version of the Engineered Now Headrest.
They are not the same low-quality imitations from China sold on many platforms.

It offers the same quality with all the same features at a remarkably lower price, plus a few upgrades. For all these reasons, they are selling remarkably well.

You can also see below that the mesh matches perfectly.

It comes with stoppers to keep the headrest locked at a certain height.

Herman Miller Aeron Headrest comparison
The original adjustment rod on the xxx has a smooth surface. Some users complain that the positioning slips too easily. The adjustment rod on this listing allows stepped adjustments to hold positions better.

It also has cushion padding to reduce the risk of scratching the frame.

Herman Miller Aeron Taiwan headrest
Cushioning material to reduce the risk of scratches.

Our version is the latest made in Taiwan and not copies made in China.

Here’s the link

Ergonomic Aeron Headrest – H3 (OEM)

Atlas Headrest

Atlas Aeron Headrest back view

The Atlas headrest was introduced in recent years, and it grew in popularity as they use the same mesh as the original Aeron chair.

This gives them the perfect match.

Here’s the link: Atlas Aeron Headrest

Here’s a comparison between the Atlas and the Engineered Now design.

Left Atlas, Right Engineered Now HR03. Frontal photo
Left Atlas versus HR03

Headrest comparison

If you want more in-depth comparisons between the headrests.

Refer to this article:  Aeron Headrest Comparison.

In summary

The Atlas headrest is a lot larger than the HR03 and more protruding. There’s also a protrusion at the back of the headrest, which makes the chair takes up more airspace.

Some users comment that the Atlas headrest obstructs headphones less. While some users comment that the Atlas push the head too forward at certain angles.

Ergonomically, the Engineered Now rest should perform better due to its fully adjustable design to fit to the person’s posture.

The OEM Ergonomic headrest is a new contender that corrects the problems of the Engineered Now and offers the best value.

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