Please check the size to see if it is suitable for your yo-yo's bearing specification before purchasing. The precision is much ordinary KK bearings, and no lubricant and other auxiliary products are needed to achieve the condition. The biggest advantage of this special bearing is that the rope be in the center of the bearing as much as possible when playing with the ball, which reduces the friction between the rope and the wall of the ball. Improve the idle time, reduce the ball power consumption, and play the feeling of more smooth and comfortable ~! [Installation method] 1, Unscrew the yo-yo, pass the bearing from the center, then screw the other half of the yo-yo until it is unscrewed. Note: Never over rotate. 2,Please apply a small amount of yo-yo grease and yo-yo maintenance oil on the side of the shaft and bearing. 3,Please note that if you apply too much, it get on the rope and affect play. Colour: silver Material: High carbon chromium bearing steel Size: 12.70 x 6.35 x 4.762mm Package Contents: 40 x bearings Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.