Insulation Black Foam Tape Adhesive Seal for Pipes, Doors, Windows - Universal Weather/Air Sealer, Waterproof - 2" x 30' Roll (1/8" Thick) Supply Grille 2/3" bar spacing - Horizontal

2/3" bar spacing - Horizontal bars are fixed at 45 degrees for Great Airflow Dynamics

"Opposing" back blades

Actual Filter Size – 17 3/4"w x 31 3/4" x 1"

Installation Location – Sidewall or ceiling

+ Product Details Perfect Fit & Easy Sizing - Designed for a 28" x 26" OR 26" x 28" duct opening (measured at the opening)

Insulation Black Foam Tape Adhesive Seal for Pipes, Doors, Windows - Universal Weather/Air Sealer, Waterproof - 2" x 30' Roll (1/8" Thick) Supply Grille 2/3" bar spacing - HorizontalInsulation Black Foam Tape Adhesive Seal for Pipes, Doors, Windows Universal Weather Air Sealer, Waterproof 2" x 30' Roll (1 8" Thick)