T-Bar Drop Ceiling Grille - Flat Plate Plaque Diffuser - 12" x 12" - 8" Collar Grille With a 6" diameter for

With a 6" diameter for the duct opening measurement

+ Product Details Size - 4"w X 18"h is the size for the duct opening measurement only

For 6" duct opening

actual front end outer dimensions are approximately 16 5/8" width X 14 5/8" height

T-Bar Drop Ceiling Grille - Flat Plate Plaque Diffuser - 12" x 12" - 8" Collar Grille With a 6" diameter for+ Product Details Size 12"w X 12"h. These are specially sized to fit into all drop ceilings, also called T Bar systems. Can be hooked up with our "Butterfly Dampers" for precise airflow control. For 8" duct opening High Quality Heavy gauge all steel construction. Installation Location Ceiling. Design These Supply Diffusers with integral round necks are recommended for heating, ventilating and cooling. Round neck to square face construction results in