It is a good quality replacement filter cartridge and best suitable for SLM, Buddy-L, Waterworks, Empire, Pelican, Recreation, Haughs, S-8 skim filter, H20 Recreation, SLM. It replaces Unicel # C-4304, Pleatco # PC7TC, and Filbur # FC-3711 and meets OEM # 137046 specifications. This 8 inch long and 4 ¼ inch wide filter cartridge has 1 15/16 inch holes both at the top as well bottom. This filter cartridge provides clean and clear water for your pools and spas free from sand and worms.