16" X 20" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 18 5/8" X 22 5/8"] Color_Red Oak Wood + Product Details Size - Compatible with Duct 4" RG1612AL actual front end outer

+ Product Details Size - 22"w X 4"h is the size for the duct opening measurement only

+ Product Details Size - 20"w X 8"h is the size for the duct opening measurement only

Actual Filter Size – 23 3/4"w x 23 3/4" x 1"

Design – Unrestricted airflow for your HVAC system - adjustable one-way louver with full horizontal airflow directional control - single deflection supply grill with 96% airflow - noise free components - no vibrating louvers etc

+ Product Details Size – 6" x 14" or 14" x 6" is the size for the duct opening measurement only

16" X 20" Steel Return Air Filter Grille for 1" Filter Removable Frame [Outer Dimensions: 18 5 8" X 22 5 8"] Color_Red Oak Wood + Product Details Size Compatible with Duct 4" RG1612AL actual front end outer + Product Details Size 22"w X 4"h is the size for the duct opening measurement only + Product Details Size 20"w X 8"h is the size for the duct opening measurement only