Winflo carbon filters/charcoal filters are perfectly designed for ductless range hood installation. They are attached to the range hood blower to clean the air before recirculating back into the house. Ductwork is not necessary. Winflo carbon filters are the solution for the kitchens that don't have an exhausting duct option. This carbon filter fits Winflo some wall mount or island range hood. Please read range hood sticker near the motor to make sure the match.