... 2,Competitive price 3,Quick delivery,good service 4,speed skate bearing As a professional skateboard bearings manufacturer, we have two ... 8x16x5mm).2,ToleranceLevels of our skate bearings include ABEC-1, ABEC-3, ABEC-5, ABEC-7 and ABEC-9. ABEC-5 ... Si3n4 Full Ceramic and Zro2 Full Ceramic,Hybrid Ceramic etc. And there are also special kinds like chromium bearing and blackened bearing. 6,LubricationMost ...