Just very difficult to get the castor wheels on. I called customer service and they were excellent. They were sending me a new bottom and 5 new castors. Fortunately I was able to get a neighbor to help me get them on and they were able to cancel that shipment to me. Chair is very comfortable and doesn't take up a lot of room as my previous chair did.
I got this chair on sale and really like it so far though note I've only been using it for a few days. Assembly: I'm not sure why so many people complained about inserting the casters. I'm a petite woman and had no issues. You push hard twist back and forth a bit and they go in without too much fuss. Easy to follow pictures and labels. No frustration assembly. The Chair: It's a fairly basic chair but very comfortable for working from home. I really love the gray/white combo as I was looking for a non-black office chair and this fit the bill.