Freedom Spas spa filter (C-4405)

Freedom Spas

Replacement numbers

Unicel C-4405, Pleatco PRB25SF-PAIR

Fits Freedom Spas.

Diameter 4-15/16" (125 mm)Length 6-5/8" (168 mm)50 sq ft1 model listed

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UnicelC-4405
PleatcoPRB25SF-PAIR (Unicel cross-reference PDF p.47: C-4405 = PRB25SF-JH-PAIR. Spec table prints PRB25SF-PAIR at 5" x 6-5/8".)
FilburFC-2387
Top2-1/8" (54 mm) / open
Bottom2-1/8" (54 mm) / open
Ø 4-15/16" (125 mm)6-5/8" (168 mm)Side view · end views belowTopBottom
Top: 2-1/8" (54 mm) / open
Bottom: 2-1/8" (54 mm) / open
Drawn to scale from the listed diameter and length and open-end sizes. Handles, threads and closed ends are drawn as symbols, not to scale. 50 sq ft media.

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Freedom Spas files this cartridge as C-4405 cartridge, in the Freedom Spas group. Numbers on the row: Unicel C-4405; Pleatco PRB25SF-PAIR; Filbur FC-2387. 4-15/16" across, 6-5/8" long, top 2-1/8" / open, bottom 2-1/8" / open, 50 sq ft.

What the sources add about PRB25SF-PAIR: Unicel's Freedom block prints this 50 sq ft row with a blank model cell: 4-15/16" x 6-5/8", C-4405, 4 oz. The note "Model dated after 1993" is the next line, under this row, not under Liberty. Filbur's Freedom section repeats that note on FC-2387 and calls the row Rainbow DSF 50, 2/set. Not indexed: no Freedom OEM number, no model name, and the body duplicates Beachcomber C-4405.

C-4405 (OEM C-4405 cartridge), Pleatco side: Unicel cross-reference PDF p.47: C-4405 = PRB25SF-JH-PAIR. Spec table prints PRB25SF-PAIR at 5" x 6-5/8"..

PRB25SF-PAIR, Filbur note: Freedom Spas section PDF p.18 (printed p.35): FC-2387, Rainbow DSF 50, 2/set, "Model dated after 1993", C-4405, 50 sq ft..

Model list attached to C-4405 cartridge: Not named, years Model dated after 1993, listed by Unicel 2026 Replacement Guide (Unicel prints the note under this blank-model row. Filbur repeats the note on the Rainbow DSF 50 row.).

Before ordering C-4405, compare it with 4CH-30 differs by Unicel 4CH-30, Pleatco PTL25P-4, Filbur FC-0141, 4-5/8" diameter, 11-7/8" long, top molded cone handle, bottom 1-1/2” male thread/MPT, 30 sq ft, note says Shown at 30 sq ft because that is Unicel's Freedom Spas line, Unicel's spec table (158 pleats, 4 oz), Filbur's size table and Aladdin 13005. Unicel's Sundance line prints the same 4CH-30 for OEM 6540-484 at 25 sq ft, and Filbur's Sundance line does too. Unicel names Franklin, Statesman and Revere. Aladdin's model field uses that same string and lists Freedom among many brands, including Dimension One and Sundance. Pleatco's Unicel cross-reference does not list 4CH-30; PTL25P-4 is Filbur's Pleatco cell.; and C-4637 differs by Unicel C-4637, Pleatco PRB37-IN-4, Filbur FC-2380, 13-5/16" long, 37 sq ft, note says Unicel's Freedom list names Concord, Patriot, Ambassador and Executive on this row only: 4-15/16" x 13-5/16", C-4637, 37 sq ft, 4 oz. The spec table gives 158 pleats, 2-1/8" open ends, and calls 37 sq ft an upgrade of the 25 sq ft C-4326 and C-4625. The brands on that spec line are Rainbow, Waterway, Morgan, Leisure Bay and Custom Molded Products, not Freedom. Filbur's Freedom section calls FC-2380 Rainbow Dynamic 37 and does not print the Concord names. PRB37-IN-4 is Filbur's Pleatco cell..

Left blank on purpose: No model name. The 1993 note does not say it replaced Liberty's C-4401. Filbur calls it Rainbow DSF 50, not a Freedom model. Duplicate of the Beachcomber C-4405 body..

Pages checked for PRB25SF-PAIR: Unicel 2026 Replacement Guide on C-4405 (Freedom Spas line, PDF p.35 (printed p.31): blank model cell, C-4405, 4-15/16" x 6-5/8", 50 sq ft, 4 oz, note "Model dated after 1993" under the row). Pleatco 2023 Catalog on C-4405 (Unicel cross-reference PDF p.47: C-4405 = PRB25SF-JH-PAIR). Filbur Catalog & Reference Guide on C-4405 (Freedom Spas section PDF p.18 (printed p.35): FC-2387, Rainbow DSF 50, 2/set, same 1993 note).

Hot tubs listed for this cartridge

The rest of the Freedom Spas model list is the Freedom Spas filter by model and year lookup.

Model / systemYearsListed by
Not named (Unicel prints the note under this blank-model row. Filbur repeats the note on the Rainbow DSF 50 row.)Model dated after 1993Unicel 2026 Replacement Guide

Check the cartridge you removed

Measure diameter, length, and both ends, then compare them with the figures above. The steps are in the measuring guide. Why the bottom decides whether it seals: open-end vs threaded filters. Power, the retainer, and not running the spa empty: how to install a cartridge. Number formats: how Filbur, Unicel and Pleatco numbers compare.

The same C-4405 number is also on the Beachcomber, PDC Spas pages.

Other Freedom Spas cartridges

All 6 Freedom Spas spa filters

Every number on this row, on one screen: cross-reference lookup. Published clean and replace intervals for this cartridge, and a buy link for the numbers above: replacement schedule and reorder. The interval comparison by brand: calculator.

Cleaner and test strips

Hose rinse and soak steps are in how to clean a cartridge. Named cleaners and strips are in filter cleaners and test strips.

Filter cleaner and test strips

Sources

Not in sources: No model name. The 1993 note does not say it replaced Liberty's C-4401. Filbur calls it Rainbow DSF 50, not a Freedom model. Duplicate of the Beachcomber C-4405 body..