Wheel Diameter 53mm Wheel Durometer/Hardness 95a Road Surface 21.2mm Wheel Width 33.42mm Crystal Cores feature Ricta's new optically clear high-performance 95a urethane. 95a high-performance urethane offers a more forgiving durometer for rough terrain with easy, consistent slides you'd normally only get on harder wheels. Ricta's latest core design provides optimal speed, reduced rolling resistance, and maintains shape integrity on landings for easy rollaway. Ricta's latest core design provides unique speed, reduced rolling resistance, and maintain shape integrity on landings for easy rollaway. Ricta Crystal Cores 95a Skateboard Wheels 53mm