EarthCare Replacement 93F Filter Set for Norpro 93 Ceramic Compost Keeper & Stainless Steel Counter Compost Crock (2) 5.5" diameter filter keeps kitchen compost bins and pail odorless. Replacement compost filter refills for Norpro compost keepers. (#83, 93, 93R and 93EB) Charcoal filters help absorb the unwanted odors that compost pails produce. Easy to replace, change every 6 months-depending on use. You can rinse your filters, but do not submerge in water.