Neutralize Odors: The Hamilton Beach TrueAir Odor Eliminator doesn?t mask pet smells food and other odors it eliminates them. The quiet fan pulls air through and the carbon filter trapping and neutralizing odors before sending fresh air back into the room for about 3 months. Replacing your Hamilton Beach True Air filters is easy. Simply place the filter in the unit fitting the notched corner of the filter around notched edge of the odor eliminator.