Premium Material-- Made from durable polyurethane material, designed to provide good grip and speed in all hardnesses and has excellent durability. 95A Hardness for Indoor Performance -- With 95A hardness, offering grip, speed and durability. These long lasting artistic wheels are competition quality & formulated to roll smoothly while providing a fantastic grip on the rink floor. Suitable Skating Style: Jam, Derby, Speed, Session. Highlights-- The inner and outer edges of the hub are oversized, which reduces the amount of urethane on the edges of the wheel. This makes it easy to perform stops and offers excellent response. The middle of the hub has room for more urethane, which offers grip, increases control, and improves ride. Note: The data are manual measurement, please allow a 1-3cm error, due to the differences between the light and the display, there will be a certain color difference, the specific received in kind prevail.