These Spindels are identical to the normal Electrospindels. But have a different type of sealing. The front and rear of the motor have an air seal. Continuously air is running through the seal, preventing fine dust from entering. This motor has been developed for very dirty environment. Especially suitable for robot milling of epoxy, which creates very fine dust, and usually a robot does not allow easy dust extraction. Which means there is a high risk of dust getting into the bearings. With this motor these issues have been solved.