Honeywell Enviracaire 33002 Carbon Charcoal Pre-filter Fits models: models 10000, 11502, 12500, 12520, 13500, 13501, 13530, 13531, 17400, 17440, 43300, 62500, 83133, 83165, 83236, 83256, 8331 part number 33002, EV-1 (EV1), EV-25 (EV25), EV-35 (EV35), EV-35A (EV35A), E33, E-33 Designed to work with Honeywell HEPA Filter 21500 & 22500 Approx. Measurements: 24" L X 1/8" W X 8" H X 16" Diameter