Product Size: 30cm diameter Product Weight: 60g Material: Fabric Sky Cross (Officially recognized by the Japan Sky Cross Association): A sport played using donut-shaped rings made of fabric. Because you walk the course, your amount of exercise naturally increases. The unique "Noruna rules" determine scoring based on whether your ring lands on top of or is landed on by your opponent's ring, making for a thrilling game where the outcome is uncertain until the very end. One official ring (sewn fabric product).