1Exercise Skills: Exercise your babys hand-eye coordination, creativity, and imagination. 2Try New Movements: Try new movements and gradually form a coherent hand and foot movement, so that the babys muscles can be developed. 3Premium Ball Bearings: The high-speed ball bearings are of first-class quality and can be played in various positions, all retractable freely. 4Increase the Fun: There is no limit to the age of 3 years old and above. Adults and children can play together to increase the fun. 5High Quality Yoyo: High-precision bearings, quality assurance, full gaming experience. Specification: Spherical: butterfly Material: aluminum alloy 6061 + environmentally ABS Weight: about 68g Diameter: about 55.9mm/2.20in Width: about 42.3mm/1.67in Shaft width: about 4.59mm/0.18in Bearing: high-precision 10-ball bearing Recycling sticker: yellow silica gel Surface treatment: bright surface Screw specification: about 4*16mm/0.16*0.63in Applicable moves: (1A, 3A5A)