Keep clean drinking water for your pet using this Premium Charcoal Water Filter Replacement. It comes in a set of 12 and is designed for use with Drinkwell pet fountains made by NISPIRA, including the Original, Platinum and Big Dog fountains, which are sold separately. Stock up on this premium water filter, so you'll always have a fresh one handy. It's a two-chamber piece that stores easily on a shelf or in a cabinet until needed. It's easy to replace, so you can put it to use quickly.