Bien Air Micromotor handpieces are available with or without brushes, depending on the age and model of the handpiece. Brushless micromotors are typically a little quieter and enjoy fewer trips to repair. The brush type models are still very competitive in performance and can be purchased here, when available, at very reasonable prices. Make sure you get models compatable with any contra angles you already have. Straight e-type with no air/water or LED should be compatible with most e-type contra angles you are currently using. Bien air, along with Kavo, helped to revolutionize the dental industry with electric handpieces capable of high speeds (200,000 rpm) and torque required for clinical preparations requiring such. Constant torque is a term often used when describing the difference between these and air driven high speeds. You almost have to try this type set up to feel the difference. 200,000 rpm is more than enough speed when torque remains consistant.