These The Heart Supply wheels are built to last. They are 52mm in diameter and have a hardness of 99a, making them reliable and stylish. The Heart Supply Skateboards Even White/Red Skateboard Wheels - 99a are sold in a set of four wheels. And yes, you need four wheels for a skateboard! Features: - Set of 52mm The Heart Supply Skateboards Even White/Red Skateboard Wheels - 99a, including four wheels - Diameter: 52mm - Hardness: 99a - Color: White/Red