Diffuser and plenum are constructed of 24 ga. Electra-galvanized and galvanized steel.  One, two, and three slots models are available, in two and four foot lengths, with one and two way pattern configurations.
 

Optional frames styles available for surface mount, Spline, and fineline applications.
 

Inlet sizes available: 6", 8", 10" and 12"
 

Standard finish is white.