The Pentair Pac Fab 174821 R is a compatible replacement for the following pool and spa filters:
The Pac Fab 174821 Comp. Pool & Spa Filter Cartridge has a diameter of 5 5/16 inches, and a length of 13 9/16 inches. This spa filter cartridge has an open top with a diameter of 2 1/8 inches, and an open bottom with a diameter of 2 inches and Male Pipe Threads (MPT). This pool filter replacement will keep the water in your pool or spa clean and clear.