Spa Filter Darlly: 42513 Baleen: AK-3011, OEM: 817-2500, Pleatco: PRB25-IN , Unicel: C-4326 , Filbur: FC-2375, Diameter: 4-15/16", Length: 13-5/16"

Filter Specifications:

• Square Footage: 25 sq. ft.
• Media/Thickness: 3
• Diameter: 4-15/16"
• Length: 13-5/16"
• Top: 2-1/8" Hole
• Bottom: 2-1/8" Hole

Equivalent to:

• Pleatco: PRB25-IN
• Unicel: C-4326
• Filbur: FC-2375
• OEM: 817-2500

This Filter Fits The Following Brands:

Waterway, Zone, American

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