Abrasion resistant endurance urethane for superior outdoor wear and great grip. Built to last with street-level 85A hardness. High rebound technology providing more speed and force with each stride. Ideal for outdoor surfaces such as asphalt and concrete. The world’s best-selling outdoor 85A roller wheel for 6 years and counting. Standard hub wheel designed for the standard 608 bearing size. Made with 24% more urethane than the competition mentioned below, meaning that not only are these wheels a fraction of the price, but they also last longer. Wheel Comparison Chart Hardness Construction Price TronX Pavement 85A Single Pour Urethane $3.99 Labeda Asphalt 85A Single Pour Urethane $8.99 Konixx Rocket 2X 84A Single Pour Urethane $7.99