Ceramic materials are available：Zirconia, Alumina, Silicon nitride and machinable ceramic...etc
General sizes：8 mm,12 mm,20 mm,15 mm,26 mm,25 mm,32 mm,34 mm etc
Cylindricity: up to 0.004mm
Inner hole tolerance: minimum machined 0.005mm
Features：flat surface, high hardness and wear resistance, can withstand continuous friction, and is not easy to fall off....
Customized：Can be custom for special sizes and shapes
Delivery times：2 -25 days(depends on the quantity)