Fiberglass duct board does not support a motorized zone damper the way sheet metal does. The EWC Controls DBA series solves this: the brackets are used to mount ND and ND-RSD style dampers to fiberglass duct board, and the ND damper submittal advises that if using duct board, additional support can be obtained by using Model DBA duct board adaptors.

The DBA-10 is the 10" size in the series, which EWC catalogs in 2" increments from 6" through 24". Standard DBA brackets are for 1" thick duct board; EWC specifies adding the digit 5 to the part number for 1-1/2" thick board, for example DBA-10-5.