One feature of the rotary viscous damper I would like to point out is the ability to function wet. Because we seal the dampers water cannot penetrate the functional area of the unit. This can be very convenient for areas where wash down, rain water, and most wet, humid environments occur. The materials we use are water and rust repellant. For example if a damper had to be used in a car wash , no functionality would be lost if sprayed with water all day long. If needed we could design the damper for use under water. Another example could be a chest freezer where wash down is mandatory. Please contact us with your application at www.mmtech.us