Bones Hardcore Skateboard Bushings Hard Black (Set Of 4): A turn for the better, the Bones Hardcore Skateboard Bushings are the preferred choice among top pros and alike. Bones patented double action, high rebound urethane provides the best response, turning and feel of any bushing in the world. The Bones Hardcore Skateboard Bushings give you a tight ride with high resistance to turning throughout the entire turning range and an ultra quick response – perfect for the freestyle skaters among you.