Fits every litter box Reduces hazardous ammonia gasses for a safe and cat-friendly litter box Unscented and non-toxic Includes reusable plastic holder and 2 filter pads Made of BPA-Free Materials Prevent cat pan odours from escaping the bin Catit Magic Blue is safe, easy, non-toxic and unscented. The Catit Magic Blue Cartridge Set is a litter box filter that absorbs and retains up to 80% of ammonia and reduces fecal odors by an average of 40%, depending on your cat's diet. How to use? 1. Place two pads into the holder 2. Put the sticker on the docking station and peel off the remaining paper 3. Attach the docking station to the top of the litter box interior 4. Insert the holder into the docking station Simply place Magic Blue in your trashcan and experience the magic every time you open the bin. The ammonia gases will be reduced by an average of 50% or more. Cartridge Dimensions : 10 cm (4") (L) x 3.5 (1") cm (H) x 7.5 cm (3") (W). What's in the box? 1 x Catit Magic Blue Cartridge Set (reusable plastic holder and 2 filter pads)