KMCF200 (set of 2 carbon filters to suit Rangehood models RHGV90, RHUC61, & RHUC91 ) The internal Kleenmaid Activated Charcoal (or “Carbon”) Filter is used on a rangehood installed in recirculating mode i.e. not vented outdoors. There are 2 charcoal filters located inside these rangehood models, which remove cooking odours from the air. They cannot be cleaned and will require replacement. The effective life of the filters depends on the type and amount of cooking you do. Generally the life of these filters is approximately six months, however always replace the filters when they no longer absorbs odours effectively.