nylon bearing
POM ring, glass ball pa66cage
wear-resisting than other plastic
self-lubricating
nonmagnetic

nylon bearing: also called together the formaldehyde, steel, are generally POM rings , PA66 / PE cage, glass ball/ceramic balls, open. The hardness of POM is better in engineering plastic, wear-resisting, And it is the most common plastic bearings, according to the different requirements of customers, can add one-sided or two-sided lid.
Advantage: wear-resisting, environmental protection, self-lubricating, absolutely electricity, no magnetic. Resistance to rust. 
Disadvantage: cannot be used in high speed and high pressure, high temperature and corrosive environment.