Guardian Antimicrobial Spa Filter Replaces Pleatco PAS50SV-F2M, Unicel 6CH-502, Filbur FC-031 Artesian Spa Antimicrobial filtration fabric Replaces Pleatco PAS50SV-F2M, Unicel 6CH-502, Filbur FC-0311 Diameter 6-3/4", Length 8", Top Handle, Bottom 2" MPT Threaded Filter area: 50 sq. ft. Used in spas made by Artesian Spas, Majestic Industries