Trion charcoal after filter for Trion portable air cleaners. Approximate size 3 1/2 x 10 1/2 x 1/2 inch thick with cardboard edge that sticks out on the 2 short ends. That cardboard edge slides into the slot on the air cleaner to hold it in place. Should be replaced every 90 days. Once the activated charcoal absorbs all the odor it can hold, it will no longer absorb odor and can not be cleaned and reused. This part number was replaced by part number 247640-001 so that is what you will receive when ordering this item.