36" X 12" Steel Return Air Filter Grille for 1" Filter - Fixed Hinged - [Outer Dimensions: 38 5/8" X 14 5/8"] w30h30 Energy Efficient – Air-tight inner AD-S-230-10x10 Width_8in Actual Filter Size 25

Energy Efficient – Air-tight inner core decreases the pressure loss and provides a more hygienic environment - high energy efficient / No fiberglass erosion into air stream

+ Product Details Size - 18"w X 10"h is the size for the duct opening measurement only

High Quality – Solid rigid steel body for durability and reliability

This grille has a high standard of design

+ Product Details Size - 14"w X 28"h is the size for the duct opening measurement only

36" X 12" Steel Return Air Filter Grille for 1" Filter Fixed Hinged [Outer Dimensions: 38 5 8" X 14 5 8"] w30h30 Energy Efficient – Air tight inner AD S 230 10x10 Width_8in Actual Filter Size 25 Energy Efficient – Air tight inner core decreases the pressure loss and provides a more hygienic environment high energy efficient No fiberglass erosion into air stream + Product Details Size 18"w X 10"h is the size for the duct opening measurement only