This replacement filter cartridge comes with a technical specification Filbur# FC-2401, Pleatco # PFF50P, Unicel # 5CH-45, and OEM # 5CH45. This product can handle a top load of 45 Sq. Ft. and is a high performance filter cartridge. This state of the art 45 SQ. FT. Freeflow spas legend filter is of superior quality as per industry standards. This filter comes with Open Hole of 2 1/8" at the top and an Open Hole of 1 1/2" at the bottom. It is 10" in length and 5 5/16" 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.