About this item These activated carbon (fiber) filters are made of high-quality activated carbon powder as the adsorption material, and the polymer bonding material is used to fix the carbon to fiber. Thick and dense carbon filters can effectively absorb and capture food odors in the compost bin, they are environmentally friendly, tear-resistant and safe to use. Effective in blocking odors unwanted. Absorbs odors from liquids and gases, ideal for capturing carbon-based impurities or organic chemicals, helping to improve indoor air quality by regulating composting emissions to ensure a clean home. An installer can last around 2 months and 3 months. It will also depend on what is put in the food waste bin, weather and many other factors, so it may only last a few weeks. But anyway, you can just replace it when you find it's time to do so. Be careful, don't leave them in the bin too long when old or they will grow and accumulate rot. These square filters are 5" x 5" fit best square compost bin lids. You don't have to cut round filters to lose them. If you have double-sided tape, you can stick it to the back of any compost bin lid, even if there isn't a custom fitment to replace the filters.