Pleatco PMA20-F2M = Unicel 4CH-252

20 sq ft hot tub filter, 4-3/4" diameter × 8-1/16" long. Top: Handle · Bottom: 2" MPT. Pleatco application: Master Spas Contractor Series (CS) 415.

Interchangeable cartridges

Unicel 4CH-252 confirmed by: Pleatco p.47 (Unicel to Pleatco cross reference) Unicel p.7 (Cartridges by series (dimensional listing))
Unicel note: Note: Cal Spa/Coleman Spa & Master Spa originals have 4-3/4" OD.

Check before you order

Unicel 4CH-252 rates it 25 sq ft (vs 20 sq ft); filter area ratings differ by maker.

Published dimensions, side by side

Each manufacturer measures a little differently. Compare these with your old cartridge.

As published by	Pleatco PMA20-F2M source	Unicel 4CH-252 source
Outside diameter	4-3/4"	4-5/8"
Length	8-1/16"	8"
Top end	Handle	/ molded cone handle
Bottom end	2" MPT	/ 2" male thread/MPT
Filter area	20 sq ft	25 sq ft
Pleats	not listed	213
Media weight	3 oz/yd²	3 oz/yd²

Where to buy

Search any retailer for 4CH-252 or PMA20-F2M. These are the same cartridge under different brand names.

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OEM part numbers this cartridge replaces

As printed in the cited aftermarket catalogs. Match the number on your old cartridge or in your spa manual exactly.

OEM number	Listed in
`FIL11100303`	Unicel p.30: OEM cross reference: Cal Spas Unicel p.32: OEM cross reference: Coleman Spas
`X268521`	Unicel p.45: OEM cross reference: Master Spas

Hot tub brands that use it

From the spa-manufacturer cross reference in the Unicel 2026 Replacement Guide. A brand may use several sizes, so check your measurements.

Cal Spas (OEM FIL11100303) Unicel p.30
Coleman Spas (OEM FIL11100303) Unicel p.32
Master Spas (models: Contractor Series 415, Clarity Spas 415; OEM X268521) Unicel p.45

FAQ

What is the Unicel equivalent of Pleatco PMA20-F2M?

The catalogs cross-reference Pleatco PMA20-F2M to Unicel 4CH-252.

What is the Filbur equivalent of Pleatco PMA20-F2M?

We did not find a Filbur equivalent for Pleatco PMA20-F2M in the manufacturer catalogs.

What size is the PMA20-F2M filter?

Pleatco lists PMA20-F2M as 4-3/4" outside diameter by 8-1/16" long, top: Handle, bottom: 2" MPT, 20 sq ft.

Which OEM part numbers does it replace?

Listed OEM numbers: FIL11100303, X268521.

Sources: Pleatco 2023 Catalog & Cross Reference Guide (Pentair) · Pleatco 2023 Catalog & Cross Reference Guide (Pentair) · Unicel 2026 Replacement Guide. Last checked 2026-10-21.