I have an older model (~8 years) and one of the wheelbase arms broke off. DXRacer was responsive to my email question and told me which base would work with my model. If you're looking for parts, the links can be found in the FAQ question: "If my chair's warranty has expired and I need to purchase corresponding parts, what should I do?"

Very comfortable! The cushions, especially in the lumbar area, also play a role. The cushion is very comfortable, not too soft or too hard. So far I have sat in it for 2 hours without any discomfort or pain in my lumbar or back.

Fantastic chair and my son loves it! The ability to lean back, the lumbar support and comfort are excellent.