Winflo carbon filters/charcoal filters with 2pcs set are designed for non-ducted/ventless range hood installation. Only fits Winflo range hoods. Filter size is 7.5 in. x 7.5 in. x 1.5 in. See manufacturer sticker inside bottom of range hood to ensure correct filter part size. They are attached to the range hood blower to clean the air before recirculating back into the house. Duct work 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 select under cabinet range hoods and select wall mount and island range hoods.