GAURDIAN ANTIMICROBIAL POOL/SPA 2 PACK Filters fit: Pleatco:PAS50SV-F2M, Unicel: 6CH-502, Filbur: FC-031 Artesian spas, MAJESTIC ANTIBACTERIAL, MICROBAN ANTI-MICROBIAL MEDIA majestic LENGTH 8'' 2" MPT fine pipe threads DIAMETER 6 3/4''