Refill filter replacement sachet with activated carbon compatible with Greensaver keeper, bluapple produce saver and other crisper Inserts Each sachet contains activated carbon and potassium permanganate While activated carbon removes any unfavorable odor from food, potassium permanganate can effectively absorb the Ethylene gas from the produce to extend the freshness Suggest replacing the filter every 2-3 months the most to keep the produce fresh and last longer Size 3.5" x 2.4". Quality meets or exceeds the leading national brand. Refill filter replacement sachet with activated carbon compatible with Greensaver keeper, bluapple produce saver and other crisper Inserts. Each sachet contains activated carbon and potassium permanganate. While activated carbon removes any unfavorable odor from food, potassium permanganate can absorb the Ethylene gas from the produce to extend the freshness. Suggest replacing the filter every 2-3 months the most to keep the produce fresh and last longer. Size 3.5" x 2.4".