This replacement filter cartridge comes with a technical specification Filbur# FC-3097, Pleatco # PDO40-4, Unicel # C-5404 and OEM # 1561-09. This product is a high performance filter cartridge. This state of the art Dimension one spas ozone cartridge filter is of superior quality as per industry standards. This filter comes with 1 15/16" open hole at the top and a 2 7/8" open hole at the bottom. It is 17" in length and 5-1/2" wide. It efficiently provides you dust, sand and worm free clean and clear water solution for your pools and spas. The best in the industry this product matches all your water purifying needs and offers quality with cleanliness and hygiene par excellence.