Spa Filter Darlly: 50401, Baleen: AK-4033, OEM: N/A, Pleatco: PPM40-4 , Unicel: C-5637 , Filbur: FC-3637, Diameter: 5-3/16", Length: 19-5/8"

Filter Specifications:

• Square Footage: 40 sq. ft.
• Media/Thickness: 4
• Diameter: 5-3/16"
• Length: 19-5/8"
• Top: 1-1/16" Hole
• Bottom: 1-5/8" Hole

Equivalent to:

• Pleatco: PPM40-4
• Unicel: C-5637
• Filbur: FC-3637
• Darlly: 50401

This Filter Fits The Following Brands:

Marquis Spa, Amish Country, Hide

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