HIGH PERFORMANCE TRANSAXLE YOYO: the transaxle is a plastic sleeve or spool that is placed over the axle and enables long smooth spins. When the player flicks the wrist, the Fireball spins at the end of the string. With another flick of the wrist, the Fireball returns to the hand. INTERMIDIATE AND ADVANCED PLAY: The responsive play is the best choice for the intermediate player who wants to perfect string tricks. It is also a great choice for the advanced player who wants to perfect looping skills. GREAT FOR KIDS OF ALL AGES TO PERFORM LIKE PRO'S!: Whether 'Walking the Dog' or going 'Around the World,' the Fireball will advance their skills to perform a wide variety of tricks. YOMEGA FIREBALL ANATOMY: Transaxle System for long, smooth spins. Modular design makes it easy to unscrew halves to untangle string or apply lubrication. Durable Polycarbonate. Round Shape. Weight: 52 g. Width/Diameter: 34.9/58.4mm. Gap Width: 2.5mm.