Pleatco reference: PRB17.5SF PR, Unicel reference: C-4401. This filter fits Spaform Spas, Balboa. Filbur reference: FC-2386. Apollo Spas

Size: 17.5 sq ft per filter - sold as a 35 sq ft pair
Outside diameter: 12.5cm
Top finish: 5.4cm hole
Bottom finish: 5.4cm hole
Length: 11.75cm