The New Platinum Drinkwell Filters are sectioned into 6 individual compartments to allow for an even distribution of charcoal throughout the filter. This provides a more consistent filtration of the water to remove bad tastes and odors, keeping the water fresher and cleaner than ever before. The filters come in packs of three, and are compatible with all Drinkwell Pet Fountain models! Features: High capacity replacement filter cartridges. Each filter is sectioned into 6 individual compartments for greater filtration. Can be used with any Drinkwell model. Filters three ways: Duo density polyester pad captures debris, Carbon impregnated pad for quick action, Charcoal divided into six segments maximizing water filtration. Instructions: The filters fits narrow side down and the black side faces the front of the fountain. The filters will slide easily into place. For Drinkwell Platinum users insert the filter into the two triangular slots in the center of the housing. For users of the original Drinkwell, the filters will fit into the housing diagonally. Rinse the filters thoroughly under cool water before placing into the housing. This will remove any loose charcoal dust, which is harmless. A small amount of charcoal dust may shed for the life of the filters. This is normal and not harmful for your pet. Filter should be changed every 4-8 weeks depending on the size and number of pets using the fountain.