Universal Type: 4pcs compost bin filters with 6.3 inch size plus 4pcs compost bin filters with 4.7 inch size are suitable for most compost bins, and you can cut its shape freely. Efficient Filtration: The kitchen compost bin filter is made of activated carbon, which can effectively absorb and capture food odors in the compost bin, keeping your kitchen fresh and odor-free. EASY INSTALLATION: Just press the replacement. filter into the compost bin lid, the square filters are also available in round lids, the edges hold it well. Eco-friendly Material: The filters are made of high quality activated carbon and are biodegradable. Packing List: 8 filters per pack, replace every 2-3 months, this pack is enough to provide you with a supply of at least 1 year or more.