Hart & Cooley 14" x 24" (Wall Opening Size) White Sidewall/Ceiling Return Air Filter Grille

Features: All-steel construction 1/3" spaced fins set at 20 degrees Effectively conceals filter Use standard 1" thick disposable filters (not included) Removable face for easy installation and cleaning Equipped with adjustable filter retainers Bright White Finish Average face velocity = 390 fpm, based on filter capacity rating of 2 CFM per square inch of gross filter area. Free area averages 75% of grille core. For quick calculation free area (sq. in.) = listed width x lengthx .75