Yoyo bearings are also called yoyo ball bearings,usually,yoyo bearings are referred miniature bearings used in yoyo,compared with common miniature bearings, yoyo bearings is with a sepcial U shape or V shape on the outer ring. Miniature bearings used in YOYO need to rotate very smoothly and freely,usually the  YoYo bearings must meet the following conditions. Firstly, long enough idling time; Secondly, low noise, no extra noise during operation; Thirdly, the outer groove of winding shall be smooth enough. Founded  in 2007,Zhangzhou Runstar Bearings Manufacturing Co.;Ltd is a professional YoYo bearings manufacturer in China,Runstar specilizes in designing and manufacturing high precisionand high speed yoyo bearings with many shapes, there are U-groove YoYo Ball Bearing, V-groove YoYo Ball Bearing and T-groove YoYo Ball Bearing in Runstar, as well as U-groove YoYo Ball Bearings with 8 cuts at request. In order to reduce friction, prolong idling time and make players have a better experience, Runstar bearing has specially designed and modified the YoYo Bearings the original seven balls into ten balls, if you hold the inner ring with one hand and turn the bearing with the other hand, the yoyo bearings can rotate for 20 seconds at least, there are chrome steel(Gcr15) and stainless steel (440 or 420) for choice in Runstar, Custom-made yoyo bearings are accepted in Runstar. All Runstar’s yoyo bearings are strictly controlled under ISO9001:2015.