Luminous Responsive Yoyo, these light-up yoyo balls K1-Plus come with a regular flat bearing. Made of durable ABS plastic, perfect for String Trick Style (1A, 3A, 5A), and delivers high performance. Hold the Noctilucent yoyo under a light or in sunlight for a few minutes to charge the glow effect. Heavier than standard yoyos and has more balance without weighting rings. A perfect toy for kids, beginners, families, etc.; Recommended for children's daily practice or competition. If a string gets stuck: 1. Remove the string. 2. Check if the ball is loose and ensure the two hemispheres are tightened. 3. Reattach the string properly. (This is crucial!) Applicable Moves: (1A, 3A, 5A) Weight: 65g Diameter: 51.03mm Ball Width: 41.01mm Shaft Width: 4.38mm Bearing: 8-ball U-bearing Screw: *16mm Color: Blue Material: ABS Package Contents: 1 * Yoyo Ball 1 * Glove 1 * Velvet Bag 5 * Ropes (random color, specified color not accepted) Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture to be slightly different from the real thing. The allowable measurement error is +/- 1-3 cm.