Spa Filter Baleen: AK-4012, OEM: N/A, Pleatco: PLW100-4 , Unicel: C-5399 , Filbur: FC-3103, Diameter: 5-7/8", Length: 25-3/4"

Filter Specifications:

• Square Footage: 100 sq. ft.
• Media/Thickness: 3
• Diameter: 5-7/8"
• Length: 25-3/4"
• Top: Handle
• Bottom: Male Slip Fitting

Equivalent to:

• Pleatco: PLW100-4
• Unicel: C-5399
• Filbur: FC-3103
• OEM:

This Filter Fits The Following Brands:

Seasonmaster (model 121 before

Filter Glossary

As you can see in this graphic, when looking at a filter's threads from the side the difference is very obvious. Standard, sometimes called "MPT" or "Male Pipe" threads are smaller and have a higher number of threads than the S.A.E. style. The S.A.E. threads are large and are square in nature almost resembling a child's toy.

• MPT: Male Pipe Thread
• FPT: Female Pipe Thread

How to measure a hot tub filter references:

Spa Care Center or Pool Care Center