This Intex filter cartridge is the type 'A' version which will fit any filter pumps attached to 8ft, 10ft, 12ft and 15ft Intex Pool. Filter Cartridges fit inside your Filter Pump and catch dirt as it passes through the system. Intex suggest that you replace the Filter Cartridge every two weeks in the summer to keep the swimming water clean. The Filter Cartridges measure 20.1cm high by 10.8cm wide. The middle hole is 4.9cm wide.