① Low noise, good sound quality

The use of ball retainers eliminates collision noise between steel balls.

② Long term operation without maintenance

The mutual friction between the steel balls has been eliminated, and a lubricating grease bag has been provided to maintain the lubricating grease, and long-term operation does not require replenishment of lubricating grease.

③ Smooth motion

There is no friction between the steel balls, which reduces the torque variation rate and enables smooth rotational motion.