The ND series of Ultra-Zone dampers was designed with the installer and homeowner in mind. With a sturdier frame, the damper installs in the duct much faster and easier and the nylon bushings insure quieter operation. This is a feature that homeowners will never hear about! Quieter operation and a longer life motor equals NO call backs.Heavy Duty Frame
Nylon Bushings for Quieter Operation
Revolutionary Motor with greater Reliability
Simple 3-wire Hook-up
ND-RSD series dampers come with a spring return style motor.