Unicel C-4405 2-Pack | 50 sq ft Rainbow DSF Spa Filter Brand_Vermont Castings Filtration is what keeps spa

Filtration is what keeps spa water clear and comfortable

and it consistently backfires

Durable & Compact: Designed for secure mounting inside or near your appliance

Pro Tip: Bromine tabs need a head start

Unicel C-4405 2-Pack | 50 sq ft Rainbow DSF Spa Filter Brand_Vermont Castings Filtration is what keeps spaThe Unicel C 4405 is a matched pair of replacement filter cartridges delivering 50 square feet of combined filtration for Pentair Rainbow Dynamic Series IV systems and Waterway skim filters. It is sold as a set of two because the system is designed around two cartridges working side by side not because two is a convenient bulk quantity. That distinction matters more than it might sound. These housings run a pair of compact cartridges in parallel