1、Made of premium aluminum alloy material,anti-deformation,anti-collision and durable to use. 2、Designed to train fine motor skills and eye-hand coordination. 3、It also can cultivate the imagination,creativity and rapid reactionability. 4、10-ball bearing provides 4.6mm gap width,fits for playing tricks. 5、Come with a string,easy to use. 6、Suitable for professionals,beginners and 8 years+ kids.Perfect choice for professionals,advanced players,beginners,kids,etc. Features: Made of premium aluminum alloy material,anti-deformation,anti-collision and durable to use. Designed to train fine motor skills and eye-hand coordination. It also can cultivate the imagination,creativity and rapid reactionability. 10-ball bearing provides 4.6mm gap width,fits for playing tricks. Come with a string,easy to use. Suitable for professionals,beginners and 8 years+ kids. Specification: Color: 1 / 2 / 3 / 4 (optional) Material: 6061 Aluminum alloy  For age: 8 years up Diameter: 56.8 mm / 2.2 in Width: 42.4 mm / 1.7 in Gap width: 4.6 mm / 0.2 in Ball weight: approx. 65.1 g / 2.3 oz (not includes strings and other accessories) String length: approx. 1050 mm / 41.3 in (for each) Package size: 103 * 60 * 47 mm / 4.1 * 2.4 * 1.9 in Package weight: approx. 79.4 g / 2.8 oz Package List: 1* Yo Yo Ball 1* String(color by random) 1* Instruction1* Yo Yo Ball 1* String(color by random) 1* Instruction