45 sq. ft. Cartridge Filter Waterway, Custom Molded Products 6CH-942 FC-0361 Diameter…………………………………6" Length……………………………………8-1/4" Top End Cap: id/config……………..1-3/4" / open Bottom End Cap: id/config…………/ 1-1/2" SAE thread The top load cartridge is used on the following spas: Custom Molded Products Single Port Front Access Skim Note: 25253 (6CH-941) and 25254 (6CH-942) required (stacked), OEM P/N 25253 & 25254 Double Port Front Access Skim Note: Two 25253 (6CH-941) and two 25254 (6CH-942) required, OEM P/N 25253 & 25254 Waterway Plastics Front Access Skim Filter Note: 817-0011 (6CH-941) and 817-0012 (6CH-942) required (stacked), OEM P/N 817-0012 Haven Spas Note: Two cartridges required (used side-by-side). Phoenix Spas Note: Two 6CH-941 and two 6CH-942 required. Sunbelt Spas Note: 6CH-941 and 6CH-942 required (stacked). Superior Spas Note: 6CH-941 and 6CH-942 required (stacked).