Black Plastic Egg Crate Filtered Return (#4989BK-xx)
STOP! Please make sure your collar/neck size is correct for all pieces in your order. Please remember, just because the collar size for one diffuser is an 8" diameter, it doesn't mean all diffusers in your building have the same collar diameter. See picture 3 above.
Black 2'x2' Plastic Egg Crate Filtered Return. Fits in a standard ceiling grid system. Available with a 14" Collar/Neck or a 20"x20" square opening. Actual OD=23-3/4" x 23-3/4" Filter not included.