1.Long life maintenance free motor from Rosenberg Germany with differential motor speed to adjust to to actual conditions.        

2.Insulation made of EPP foam with light weight and high noise reduction ability that can withstand water and moist. EPP foam is 100% recyclable and non-toxic that will lessen the environment impact.            

3.When the temperature difference between the inside and outside is almost equal, the intelligent automatic air valve open to bypass the air and reduce the motor resistance for energy saving.

4.The energy saving effect is up to up to 82 %, Equipped 5V DC step motor.