24" X 18" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling Round Damper Ring + Product Details Size -

+ Product Details Size - 36"w X 6"h is the size for the duct opening measurement only

Actual Filter Size – 17 3/4"w x 21 3/4" x 1"

Check Out This Asin For Matching T-Bar Drop-Ceiling Grille: B007CNEJZK

The grille comes with all necessary screws for a secure fit

Design – Fixed Hinged for easy filter change & cleaning - uses a 1" thick filter

24" X 18" ADJUSTABLE AIR SUPPLY DIFFUSER - HVAC Vent Duct Cover Sidewall or Ceiling Round Damper Ring + Product Details Size -+ Product Details Size 24"w X 18"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 25. 875" width X 20" 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