Optional Ductless Kit For Broan Bwp Series Range Hoods Optional Non-Duct Kit For Use With Broan? Bwp Series, 24", 30", 36" Hood. Ductless Kit Will Filter Air Through Charcoal Filters And Recirculate It Back Into The Kitchen. For Use With Filterbwpts (Sold Separately) Replacement Filters To Keep The Kitchen Smelling Fresh.