EWC® DHK Damper Hardware Kit
The versatile DHK damper Hardware kit is compatible with original ND and ND2 rectangular dampers. It also works with URD and RDN style round dampers. The DHK will not work on a and damper with a motor side dimension of 8 in or less. If your damper is 8 in or less, the entire damper must be replaced.
EWC® Damper Hardware Kit, For Use With: Retrofitting The MRK On Older Damper Models