HQRP Foam Pre-Filters trap any large debris and hair in the water before they reach the pump providing cleaner water to your pet. These foam filters help keep the pump cleaner in between cleanings and maintain the fountain s flow rate. Compatible with Petsafe Drinkwell RF360PRE; Drinkwell 360 Plastic D360-RE Pet Fountains. Using filters properly and changing regularly they help keep the water cleaner and fresher while extending the life of your Pet Fountain. Filters may be rinsed out when the Pet Fountain is cleaned. Replace the Foam Filter every four to six weeks depending on the location of the Pet Fountain and the number of pets using it. If you do not intend to replace the filter at the time of cleaning rinse the Foam Filter thoroughly with fresh water. !!! Never wash the filters with soapy water as the soap residue will seep into the filters and cannot be removed. Only rinse the filters with water. Place the Foam Filter around the Pump. The rounded side of the Foam Filter should be directly in front of the Faceplate on the Pump. Make sure the electrical Power Cord runs over the top of the Foam Filter not underneath it as this will keep the Foam Filter in place. Disclaimer: This is not an Original Equipment Manufacturer (OEM) product HQRP branded product is a replacement. All brand names and logos are registered trademarks of their respective owners. Any use of the brand names or model designations for this product are made solely for purposes of demonstrating compatibility.