36" X 12" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling Color_Black This grille is ideal for

This grille is ideal for both sidewall and ceiling installations

+ Product Details Size - 18"w X 30"h is the size for the duct opening measurement only

and Diffusers

+ Product Details Size – 10" x 20" or 20" x 10" is the size for the duct opening measurement only

The first number in a grille size

36" X 12" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling Color_Black This grille is ideal for+ Product Details Size 36"w X 12"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 37. 875" width X 14" height. High Quality High quality steel construction, no scuff powder coat durable finish, smooth, shiny, scratch resistant, no sharp edges, 2 recessed screw holes on each side with screws included, screws same color as vent cover, easy installation. Adjustable airflow control Adjustable airflow