Editorial Review New in factory packaging- Guardian Filtration Products Filter Cartridge - Made in the USA! Replaces the following: Beachcombers Spas - OEM part number 3005815 Bull Frogs Spas - OEM part number PR. Top Load Cal Spas - OEM part number 17-2380 Coast Spas - OEM part number 817-500 Custom Molded Products EZ Twist Skim - OEM part number 25391 Hydropool Canada - OEM part number Top Load Cartridge Leisure Bay Rec Warehouse - OEM part number 817-5000 Maxx Spas Canada - OEM part number 17-2380 Morgan Spas - OEM part number 17-2380 Rainbow Plastics In Line / Top Load - OEM part number 17-2380 Viking Spas In Line / Top Load - OEM part number 17-2380 Vita Spa / DM Industries Le Cirque - OEM part number 212320 Waterway Plastics In Line / Top Load - OEM part number 817-5000 Rainbow Dynamic 50 03FIL1600 100533 6540-471 R173434 3301-2145 5001 Dynamic Series I RDC-50 RDC-50S R173430 17-3430 R172380 Series II and III RTL-50 RCF-50 17-175-1595 73533 212320 LE CIRQUE 4900-41 Series IV DFM Series IV DFML 373045 17-175-1596 APCC7150 15002 FIL1110022 PRB 50IN PRB50-IN-Z Other popular brand part numbers: Unicel C-4950, C4950 (Upgrade from 25 sq. ft. to 50 sq. ft. for Unicel C-4325, C4326) Filbur FC-2390, FC2390 Pleatco PRB50-IN, PRB68