The Aztek Iris Wheel is constructed using a two-piece 6061 aluminum hollow core to reduce weight. A tasteful contour gives it a stunning new look. They've switched to a new, super high-rebound urethane formula to give you one of the smoothest, fastest wheels ever made. All sitting on the highest quality bearings they could source. Aztek continues their streak of creating the highest quality products at the best prices, designed for the riders, by the riders. The Iris wheel is proof of progression within the scootering industry.