Premium Charcoal Water Filter Replacement (2-Chamber) for Drinkwell Pet Fountain By NISPIRA - 12 Filters 12 premium charcoal water filters by NISPIRA replace drinkwell water filters (2-chamber) Fit models: Original, Platinum, and Big Dog fountains Suggest replacing filters every 2 to 4 weeks to keep the water clean Individual polybagged and sealed to keep the filter clean. No retail packing Food grade activated charcoal. Quality meet or exceed original standard. Solely distributed by Coffee and Toy