I bought these to trade for the plastic casters on my office chair that were cracking and tearing up the floor. I had read a bunch of reviews and researched several different ones and took the chance on these. I am very happy. it has been about 3 weeks only minimal wear mostly just dirty and the easiest ride ever. The biggest negative I read in reviews was that it was hard to turn/change direction and that is true but its not a deterrent. If you change in a circle so the wheels dont have turn. Its like gliding its soo smooth. thought i am not sure about use on carpet even low pile. they are essentially roller blade wheels and if you ever go the the skate rink you should notice how your wheels react to the different floors. Best on the rink 2nd on the tile and least on the very low pile carpet. If you have carpet I highly recommend you get a floor mat.

I agree with everyone else, that these single wheel castors are so much better than the original double castors that came on the chair when purchased. I'm very happy with how easily the chair glides across ceramic tiles and carpet now.

I've had these for 1.5 months and no ball bearings have fallen out as other users have experienced. They work well on my hardwood floors and have not scratched them. I use them 5 days a week, 8 hours a day. So far so good. I do have an issue with the manufacturer "8T8". The wheel box makes the claim that there is a Lifetime Guarantee on the wheels. That would be great, except there is no contact information for 8T8 on the box. If you Google the company you will find nothing. So, I am removing a star for false advertising. It seems so dishonest and does not give me confidence in the product's long term quality.
If I start to experience issues with the wheels, I will update my review.

UPDATE: February 2021
After 8 months, my wheels are still going strong. No scratches on my hardwood floors and no ball bearings have fallen out. Woo!

I got these replacement wheels, for an old office chair that I love. It was impaled in a self-made crater in my chair mat. Moving around was impossible and I was tired of replacing chair mats.

I pulled off the old wheels using a large flathead screwdriver to wedge between wheel base and chair, while tugging. Eventually, all came off except one, where only the head came off, and wheel stem stayed on. Had to pry that one off with pliers.

Once that was done, I attached all the replacement wheels easily; like butter - as they say.

I tossed out the chair mat, and put my upgraded chair back.

First impressions - I think these wheels, would work amazingly well on bare floors and non-pile carpeting (as used in basements and outdoors) As is, I have a medium pile carpet in the room - which already has indentations from the old wheels. So moving around is still a bit difficult, but that is not the fault of the wheels. In time, I expect that will get easier. It's already a vast improvement, over the old wheels.

I highly recommend these, and have already added them to my GIFTS FOR OTHERS wishlist (of course, it's private!)

Next up - getting another set for my chair at work! (flat basement carpeting)

I've had my Aeron chair for 20+ years and the "˜stock' wheels worked fine on a Berber rug in my office. We recently bought a new home and I had my office done in hand scraped Brazilian walnut. The stock wheels sounded like they were scraping another layer off the floor and they locked up and wouldn't turn. I guess I got used to them before the move.

I ordered these, installed them in about 5minutes, and the chair rolls silently. And SO MUCH more easily.

This is by far the best upgrade to a $1500 chair ever. Herman Miller should be embarrassed by the crappy wheels on the Aeron chairs.