Keep recycling bins smelling fresh with the Avanti Compost Bin Carbon Filter. Always keep your compost bin smelling fresh we recommend that you change your filter every 3-4 months. Simply replace the carbon filter when the bin starts to smell nasty, this is one of those nifty gadgets that will quickly become an essential item. Can be trimmed to fit smaller bins Made from activated carbon Help absorb nasty odours in your compost bin Filter is designed to last 6 months Set of 6