Made of 100% stainless steel Double outer and inner Shielding structure Internal coil made from high-temperature tolerant, copper wire Efficiently protecting the motor under high temperatures environment Extended motor's service lifetime Water-filling lubricated rotor with top and bottom graphite made bearing and thrust bearings made with high precision Co-axial rotation efficiently reduces motor vibration and noise and extended its service lifetime Built-in integrated variable frequency converter with intelligent speed control algorithms with a maximum speed 6000rmp.