This replacement filter cartridge comes with a technical specification Filbur# FC-2399, Pleatco # PFF25P4, Unicel # 4CH-22 and OEM # FF-150. This product is a high performance filter cartridge can handle a top load of 25 sq. ft. This state of the art 25 sq ft Freeflow Spas TLX, RLX filter is of superior quality as per industry standards. This filter comes with 2 1/8" open hole at the top and a 1 1/2" Open Hole at the bottom. It is 6 5/8" long and 4 15/16" 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.