This replacement filter cartridge comes with a technical specification Filbur# FC-3101, Pleatco # PLW50-4, Unicel # C-5350 and OEM # C5349. This product can handle a top load of 50 Sq. Ft. and is a high performance filter cartridge. This state of the art 50 sqftSeasonmaster (Model 121 before 1994) filter is of superior quality as per industry standards. This filter comes with semi-circular handle at the top and a male slip fitting w/ moulded o ring at the bottom. It is 712-3/4" in length and 5 7/8" 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.