- 1" perimeter flange provided for easy installation.
- Design includes 1/2" drywall lip and rounded corners for added safety.
- Opening 1/4" oversized to accommodate register/grille.
- Dual Bead design for added strength.
- Black diffuser board coated with EPA registered anti-microbial protective acrylic agent along air stream side.
- Collar installed with expansion lock and then sealed air tight with hot melt glue.