Custom Molded Products hot tub filters
The Unicel 2026 Replacement Guide lists 6 of the cartridges on this site for Custom Molded Products. Many tubs use only one of these, so measure your old filter or check the number printed on its end cap.
| Cartridge (Pleatco / Unicel / Filbur) | Diameter × length | Sq ft | Models | Custom Molded Products OEM # | Source |
|---|---|---|---|---|---|
| PWW10 / C-4310 / FC-3077 | 4-1/4" x 4" | 10 | Front Access Skimmer | 25249 | Unicel p.33 |
| PRB25-IN / C-4326 / FC-2375 | 5" x 13-5/16" | 25 | Top Mount Skim, EZ Twist Top Mount Skim, Top Load Pressure | 25392 | Unicel p.33 |
| PRB35-IN / C-4335 / FC-2385 | 5" x 9-1/4" | 35 | Top Mount Skim, EZ Twist Top Mount Skim, Top Load Pressure | 25393 | Unicel p.33 |
| PRB50-IN / C-4950 / FC-2390 | 5" x 13-5/16" | 50 | Top Mount Skim, Top Load Pressure, EZ Twist Top Mount Skim | 25391, 25393 | Unicel p.33 |
| PWW50P3 / 6CH-940 / FC-0359 | 6" x 7-5/8" | 50 | Single Port Front Access Skim, Double Port Front Access Skim | 25252 | Unicel p.33 |
| PRB75 / C-4975 / FC-2395 | 5" x 20-1/8" | 75 | Top Mount Skim, EZ Twist Top Mount Skim, Top Load Pressure | 25390 | Unicel p.33 |
If your Custom Molded Products filter isn't here, it may not be in our checked list yet. We only publish matches we can confirm in a manufacturer catalog.