Coleman/Maax 3301-2145 Filter Cartridge
Coleman/Maax OEM number • 50 sq ft • 5″ OD × 13.3125″ long
3301-2145 is Coleman/Maax's number for this cartridge, not a part you have to buy from Coleman/Maax. The filter itself is a 50 square foot cartridge measuring 5 inches across and 13.3125 inches long, and Pleatco, Unicel, and Filbur all build it. If you read 3301-2145 off an old cartridge or found it in your manual, any of the numbers below drops into the same housing.
Coleman/Maax also lists 100533 against this cartridge. Different numbers on paper, same filter in the box.
Fitment notes
2-1/8 inch open top and bottom. Drop-in. Jacuzzi J-200 series 2005+, also Caldera Oasis 2002-2009. The 50 sq ft workhorse of the family: replaces Pentair Rainbow Dynamic 50 in-line cartridges (Dynamic Series I through IV), Beachcomber 3005815, Sundance 6540-471, Coleman Spas 100533, and Waterway TWM filter packs. Unicel notes it as the upgrade for 25 sq ft cartridges in the same 13-5/16 inch shell. Both cross-reference sheets also file it under Bullfrog Spas.
What to buy instead
Replacements for the Coleman/Maax 3301-2145
Each button searches Amazon for one of the numbers this cartridge is sold under. The OEM version is usually the most expensive of the set and the aftermarket versions are the same physical filter, so it is worth checking all of them before you order.
Every number for this filter
| Brand | Part Number | Type |
|---|---|---|
| Coleman/Maax | 3301-2145 | The number you searched |
| Pleatco | PRB50-IN | Aftermarket equivalent |
| Unicel | C-4950 | Aftermarket equivalent |
| Filbur | FC-2390 | Aftermarket equivalent |
| Aber Hot Tubs | 03FIL1600 | Other OEM number |
| Beachcomber | 3005815 | Other OEM number |
| Caldera | 302005 | Other OEM number |
| Caldera | 73533 | Other OEM number |
| Coleman/Maax | 100533 | Other OEM number |
| Custom Molded Products | 25391 | Other OEM number |
| Guardian | 413-212-02 | Other OEM number |
| Jacuzzi | 373045 | Other OEM number |
| Jacuzzi | 373045J | Other OEM number |
| Pentair | 17-2380 | Other OEM number |
| Pentair | R173434 | Other OEM number |
| Sundance | 6540-471 | Other OEM number |
| Waterway | 817-5000 | Other OEM number |
Full specs, the cartridge diagram, and the complete compatibility list live on the PRB50-IN cartridge page. You can also see every 5″ × 13.3125″ cartridge if you are checking a measurement rather than a part number.
Equipment that uses this cartridge
Looking for a different model? Browse every Coleman/Maax model we cover.
Frequently Asked Questions
What filter replaces the Coleman/Maax 3301-2145?
The PRB50-IN replaces it directly, and so does every cross-reference for it: C-4950, FC-2390. All of them are the same 50 sq ft cartridge at 5" outer diameter and 13.3125" long. Buy whichever is cheapest at the time with solid recent reviews. The same cartridge also shows up as Aber Hot Tubs 03FIL1600, Beachcomber 3005815, Caldera 302005, Caldera 73533, Coleman/Maax 100533, Custom Molded Products 25391, Guardian 413-212-02, Jacuzzi 373045, Jacuzzi 373045J, Pentair 17-2380, Pentair R173434, Sundance 6540-471, Waterway 817-5000, so those are not different filters either.
Is the Coleman/Maax 3301-2145 the same as the PRB50-IN?
Yes, physically the same filter. Coleman/Maax 3301-2145 is an OEM number, meaning it is the code Coleman/Maax put on the cartridge that shipped with the equipment. Coleman/Maax does not manufacture cartridges. Pleatco, Unicel, and Filbur do, and they sell the identical part under their own numbers at a lower price. Match the dimensions against your old cartridge before ordering and you are covered.
Do I have to buy the Coleman/Maax version?
No. Nothing about the housing requires an OEM-branded cartridge, and the warranty on your equipment is not voided by using an aftermarket filter that meets the same spec. The reason to buy OEM is convenience, not performance. The reason not to is price, which is often a meaningful gap for an identical part. What matters is that outer diameter, length, and end-cap style all match.
What size is the Coleman/Maax 3301-2145?
5 inches in outer diameter, 13.3125 inches long, with 50 square feet of filter media. Both measurements need to land within about an eighth of an inch, and the end caps have to match so the cartridge seats correctly when you close the lid. Measure your old one rather than trusting a number that has worn off the label.
Last verified August 2026