Unicel - 8316 replacement filter cartridge provides you complete protection from all wastes from dust, worm or anything else. This 4" open hole, both from bottom as well as top, complies with the OEM specifications, CCX1500RE. Filter cartridge is made of polyester material up to cent per cent level. It can be fitted with your pool or spa very easily without any hassle. It is 150 sq. ft. Hayward Xstream CC1500 and best of quality products.