Home › Caldera › C-4950 cartridge (OEM 302005)
Caldera OEM 302005 spa filter (C-4950)
Listed for: Caldera (Watkins) — unverified
Fits Caldera OEM 302005, 73533, 76076 unverified
Ø 4-15/16"L 13-5/16"50 sq ft| Unicel | C-4950 |
|---|---|
| Pleatco | PRB50-IN |
| Filbur | not sourced |
| Top | 2-1/8" / open |
| Bottom | 2-1/8" / open |
Retailer search links — see disclosure. Verify dimensions before ordering.
Source note: OEM list ambiguous across lines
How to confirm this is your filter
Pull your current cartridge and measure it end to end, including any handle, and across the widest point of the pleats. This cartridge measures 4-15/16" in diameter and 13-5/16" long, with a 2-1/8" / open on top and a 2-1/8" / open on the bottom. The bottom fitting matters most: a cartridge with the right diameter but the wrong thread or open-end size will not seal in the filter housing, letting unfiltered water bypass the media.
The 50 sq ft rating describes the pleated media area. Caldera housings are designed around a particular cartridge, so choose a replacement with the same size and fittings rather than a larger area rating. Unicel C-4950 and Pleatco PRB50-IN are cross-referenced to each other in the Pleatco 2023 catalog, so either should fit the same housing. Caldera has used 3 OEM numbers for this cartridge; any of them should map to the same replacement.
Similar-diameter Caldera cartridges
- C-4335 cartridge (OEM 74148) — 4-15/16" × 9-1/4"
⚠ Unverified / possible conflict: this row has not been fully confirmed against a second source. Gaps: OEM list ambiguous across lines; no Filbur equivalent sourced; no model-year range in source. Measure your old cartridge before ordering.