AIRTEC MV-4 4-Way Diffuser Grille

AIRTEC Mv4 4-way diffuser grille for 6/7/8" duct.  note: product includes adjustable airflow damper - but no backdraft damper.  See related products for backdraft dampers. Mv4 4-way ceiling diffuser grille. Ceiling diffuser grille with adjustable collar. 4-Way assembly. The MV-4 mv with its unique design and contractor friendly engineering saves money by reducing installation time by up to 80%. a diffuser, boot and damper all in one, it installs in seconds with just a few easy steps. Features: - will accept 6, 7, and 8 inch duct sizes using tear-away bands so there is no cutting required. - mounting clips rotate into position securing the unit to the ceiling material quickly and easily. - an adjustable fixed-position damper allows you to regulate the mount of air moving through the grille. - includes 1 tie strap a= 11 1/4 b= 9 1/4 c= 3/4 D= 1 3/8 e= 3 1/4 f= 5 1/4 g= 7 1/4.