The Unicel C-8399 R is a compatible replacement for the following pool and spa filter cartridges:
The Unicel C-8399 Comp. Pool Water Filter Cartridge is constructed with 100 sq. ft. of premium media area and sharp pleat folds to capture contaminants in your swimming pool and spa water. This pool filter cartridge, also known as the Filbur FC-3965, measures 8" in diameter and 16 1/2" in length with a Closed Handle top style and 3 3/4" Open bottom style. This compatible Unicel pool filter also features break-resistant bands and reinforced antimicrobial end caps.