This afternoon at work one of my friends Tina who is a massage therapist told me that the round chair in the room needs to be fixed. It needs to change the wheels because the knurled knobs is broken. I do not any idea about knobs, but she said fix or buy a new one. I think it is better to buy a new one because the round chair is very important in the room. They keep using it when they are doing the massage so they probably need a new one.