Cookology Universal CF300 Recirculating Filter - Carbon Sheet This carbon sheet is required for our Cookology Range of Visor Hoods when you are not ducting the air in your kitchen outside via a vent for instance if your cooker or hob is against an internal wall. Carbon filters are designed to absorb smells from cooking before "recirculating" the air back into your kitchen. You need to cut these filters to size, which means you can fit these universal carbon filters to most cooker hoods. The sheet comes folded and measures: 53cm by 26cm. These filters fit the following models: VISOR500BK VISOR500SS VISOR500WH VISOR600BK VISOR600SS VISOR600WH This High Quality Carbon Sheet will also fit most other Chimney Cooker Hoods - Simply Place the Sheet over the Grease Filters and the Carbon will Clean the Air before it Enters the Motor.