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FREE refund/replacement until Jan 31, 2026
To qualify for a full refund, items must be returned in their original, unused condition. If an item is returned in a used, damaged, or materially different state, you may be granted a partial refund.
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Availability:
12 left in stock
Arrives
Tuesday, Jan 27
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Features
- Made to Fit Only Herman Miller Aeron Size B Chair
- Will NOT Fit Aeron Size C or Size A Chairs
- NOT Compatible with Aeron Remastered. Mirra 1 or Mirra 2
- Fuss-Free Installation - No need to call a handyman to put these chair seat replacements in place. This new Aeron chair seat comes with a manual that'll help you remove and replace your old seat.
- Ready To Use - With this new Replacement Seat, there's no need to assemble mesh, and foam required. The seat itself comes ready to install so you'll only need a few minutes to revamp your Herman Miller Classic Aeron desk chair.
- Fits Your Herman Miller Chair - Measuring 20.25 inch Width x 18 inch Depth x 6 inch Height, our Herman Miller Aeron replacement parts are designed to fit any Classic Aeron chair size B. Replace your old chair seat with great ease!
- Sit Comfortably - This seat is made of filament which offers fantastic ventilation, so you can stay cool all day. Our seat's black mesh fabric also matches the mesh of Herman Miller Aeron chairs.
- Tough & Durable - Our Aeron Seat Replacement parts feature a reinforced, heavy-duty frame to ensure that it won't break, crack, or get damaged easily. Sit on your new cushion without worries!
Brand: FOAMON
Color: Graphite
Product Dimensions: 18"D x 20.25"W x 6"H
Size: SIZE B MEDIUM
Back Style: Solid Back
Brand: FOAMON
Color: Graphite
Product Dimensions: 18"D x 20.25"W x 6"H
Size: SIZE B MEDIUM
Back Style: Solid Back
Special Feature: Durable
Product Care Instructions: Wipe Clean
Unit Count: 1.0 Count
Recommended Uses For Product: Office
Maximum Weight Recommendation: 300 Pounds
Style: Classic
Pattern: Solid
Finish Type: Powder Coated
Room Type: Office
Age Range (Description): Adult
Included Components: User Manual
Theme: Professional classic
Shape: Rectangular Prism
Model Name: Aeron Seat
Arm Style: Armless
Surface Recommendation: Hard Floor
Furniture base movement: Swivel
Indoor/Outdoor Usage: Indoor
Furniture Finish: Graphite
Seat Depth: 18 inches
Fill Material: Foam
Cushion Style: Boxed Edge
Leg Style: Pedestal
Reclining Position Count: 1
Is Customizable: No
Is Foldable: No
Chair Backrest Width: 20.25 Inches
UPC: 860003555958 860003555965
Form Factor: Plastic
Manufacturer: FoamOn
Assembly Instructions Description: Included
Item Weight: 4.6 pounds
Item model number: Aeron Size B
Date First Available: September 30, 2020
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Tuesday, Jan 27
Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Learn more about financing & leasing here.
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Top Amazon Reviews
This replacement seat for my Size B Aeron chair fit perfectly and matched the original in both comfort and quality. The mesh feels sturdy, supportive, and identical to what came with the chair originally. Installation was simple, and once it was on, I honestly couldn’t tell the difference. If you’re looking to refresh your chair without replacing the whole thing, this is the way to go. Solid product.
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Reviewed in the United States on April 29, 2025 by Hades
Wow, am I impressed. My package arrived with very impressive contents. The seat was provided inside a wonderful case along with a package of all the tools required for the installation and very detailed instructions. The replacement took only 15 minutes for the changeout. Everything is quality and great. Herman Miller is absolutely the best. The chair I have if comfortable and functional. adjustment capable and looks great.
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Reviewed in the United States on April 14, 2025 by Terry Hansen
I've had my Aeron chair for nearly ten years. I picked it up used to replace my crappy old chair from one of the big box stores when it finally gave up the ghost. So recently I heard a "crack" and saw that the back frame of the seat had finally worn down and broken. I was beside myself. I didn't want to buy another chair, so I looked for repair shops in the area. One of the shops referred me direct to this product page and said, "order this, and if you want, I can install it." So I did. Fast forward and, still sitting on the broken seat, busy with work, I decided to look up what the repair entailed. I found a tutorial on youtube. Four bolts for the seat. Two nuts to transfer the j-bars. I figured I could handle it. This replacement seat kit came with the hex wrench needed to undo the seat, and a fitted wrench and a T25 torx driver to quickly transfer the j-bar. It took a few minutes, and a bit of leaning in because the bolts were really in there, but the replacement was easy. I literally didn't take out my toolbox because I had everything I needed in the kit. Really well designed chair and replacement was super easy. Five stars.
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Reviewed in the United States on January 11, 2023 by Matthew Medeiros
This is a perfect fit for our Aeron chair that fell apart after more than 25 years of use. It seems to be as good quality wise as the original and was straight forward to install. Very comfortable with the same feel as the original.
Reviewed in the United States on February 2, 2025 by Milton C
A very uncomfortable replacement for the original seat. There is a ridge of foam at the front edge that hits right across the back of the thigh that isn't there in the original - I compared them. The whole point of the real Aeron seat is that it doesn't do this, you can sit for hours without your legs getting constricted. This is really uncomfortable and I'm thinking about returning it. Trouble is that it was such trouble to install I don't want to have to do that again. I'll live with it for a couple of days and see how it goes. But if I were to try this in a store I would definitely not buy it. Update, after sitting on it for a couple of hours I'm returning it. This is nothing like the real thing. It's so uncomfortable that it's unusable. With my old seat restored, though not perfect, my chair now feels right again. Final grace note: the tools supplied DON'T FIT and are useless. I used my own tools to make the original swap but tried theirs for the restore, The big hex wrench that fits the hip bolt does fit, but the others don't. So you'll need your own tools. Word of warning, the smaller wrench for the seat bars is NOT 4 mm. It's maybe 3.5. I have no explanation for all the favorable reviews. I downgraded from 2 to 1.
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Reviewed in the United States on December 15, 2024 by stemper
This is a third party replacement for the seat of an Aeron chair size-"B". It fits PERFECTLY for a size B. If you read someone complaining that it doesn't fit, it is because they ordered the wrong item OR the wrong item was shipped to them. But the item listed here, the one I have received fits a size B perfectly! NOTE: The amazon listing has clear images showing the dimensions of a size-B and size-C chair seat. It also has (and I found this to be the most useful) an image illustrating how the back of the chair has TWO screws for a size-C chair and ONLY ONE CENTERED screw for a size-B chair. I included a photo of my size-B chair for illustration. The good: - It fits perfectly and it's easy enough to replace. The Bad: - The product arrived with a torx screwdriver instead of a 4mm hex key. If you have a set of hex key at home, you're good. Otherwise get one here with a 4mm key. (Note: I only had an imperial set of hex keys and I found and used on that was close enough to hold securely) - The instructions are terrible (mostly ass covering with CAUTION boxes). But it's easy to install. Here are the simpler instructions: Removing the old seat: 1) Remove the large side screws holding the seat of the chair using the larger 6mm hex / Allen key 2) Remove the 2 sets of nuts/bolt forming the "collarbone" connector below the chair, using the provided 10 mm socket and the (or your) 4mm hex / Alen key Putting in the replacement seat: 1) Attach and screw in the 2 sets of nuts/bolt forming the "collarbone" connector below the chair, using the provided 10 mm socket and the 4mm hex / Alen key. ** IMPORTANT** do these ones first or (like me) you will have to redo it... if you put the larger screws in first, you won't be able to access the space to put in those smaller ones after. 2) Align the seat, insert and screw in the large side screws holding the seat of the chair using the larger 6mm hex / Allen key Conclusion: Bad instructions, wrong tools (but hey, they **included** tools, so it's not too bad!). Great seat, that fits perfectly! Verdict: If you have a size-B chair and need a new seat: GET IT herre!!
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Reviewed in the United States on January 6, 2023 by Christian Christian