To maintain your pet’s health and well-being, regularly check your dog or cat’s feeding and watering systems’ parts and accessories for replacement. This Replacement Reservoir is designed specifically for use with the Deluxe Fresh Flow Fountain, in sizes medium (50 oz.), large (108 oz.), and jumbo (216 oz.). To ensure a proper fit, be sure to match your pet’s feeding and watering system with the appropriate product/item number for this replacement reservoir. A cap is not included with this replacement reservoir.