Click or scroll to zoom Tap or pinch to zoom Tron MEGA Hz Indoor Roller Skate Wheels by HockeyGear.Com $3.99 72MM - $3.99 72MM Size 1 2 3 4 5 6 7 8 9 10+ Quantity Quantity Add to cart Slot Core Technology increases rebound and overall grip. Test Proven Urethane. High rebound urethane for superior grip and wear. Great performance at a reasonable price. DUROMETER 74A