Signature Spas hot tub filters
The Unicel 2026 Replacement Guide lists 2 of the cartridges on this site for Signature Spas. 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 | Signature Spas OEM # | Source |
|---|---|---|---|---|---|
| PRB25-IN / C-4326 / FC-2375 | 5" x 13-5/16" | 25 | not specified | not listed | Unicel p.55 |
| PRB50-IN / C-4950 / FC-2390 | 5" x 13-5/16" | 50 | not specified | not listed | Unicel p.55 |
If your Signature Spas filter isn't here, it may not be in our checked list yet. We only publish matches we can confirm in a manufacturer catalog.