These are heavy and solidly built stools. Assembly is simple. 
The seat material feels like a urethane type of product and tries it's best to look like reasonable pleather.  The padding is substantial. 
One thing I would caution people with is: it is possible that a person could catch their fingers between the bottom of the seat and the metal beneath the seat. There is a sharp metal edge where ones fingers could get seriously cut while rotating on the seat, (if you were to have your fingers holding around the bottom of the seat while sitting around turning.)