Captain's Compass Replacement Hamilton Beach Carbon Pre-Filter 4-Pack True Air 04383, True Air Glow Allergen Reducer 04385, TrueAir Compact Pet Air Purifier 04384. 990051000 High Quality Carbon filter material Made in the USA from BulkFilter Brand material 4-Pack of pre-filters Designed to Fit True Air Air Purifier 04383, True Air Glow Allergen Reducer 04385, TrueAir Compact Pet Air Purifier 04384 Each pre-filter measures 11.5"x5"x.2" Designed for use with Hepa filter part #990051000