PERFECT FOR CATS or Small Dogs; my dog wasn’t a fan. Lol I followed the instructions; soaked the filter, and tested it out, but my dog wasn’t interested. Sensor is on point, and the fountain itself is VERY quiet, but I think it may be too shallow for dogs..? $25 Obo The Brookstone Motion Sensor Waterfountain offers a convenient drinking fountain that entices your pet to drink. Activated motion sensor dispenses water when your pet is close by, providing constant water flow. Activated carbon filter included. Innovative sensor water fountain encourages your pet to drink by dispensing water when he or she is in close proximity Activated motion sensor dispenses water when pet is within 3 feet and 180 degrees from the fountain Constant water flow both oxygenates the water and entices pet to drink Replaceable activate carbon filter removes bad tastes and odors Plastic Holds up to 3 liters of water Measures 8” L x 8” W x 7” H Weighs 2.5 lb. Limited lifetime manufacturer's warranty