Sundance Spa Filter Darlly: 40402 Baleen: AK-3031 Unicel: C-4440 Diameter: 4-5/8", Length: 16-3/4"

Filter Specifications:

• Square Footage: 40 sq. ft.
• Media/Thickness: 4
• Diameter: 4-5/8"
• Length: 16-3/4"
• Top: Castle
• Bottom: 2-1/16" Hole

Equivalent to:

• Pleatco: PSD40-4
• Unicel: C-4440
• Filbur: FC-2710
• OEM: 6540-495

This Filter Fits The Following Brands:

Sundance Spas, Jacuzzi Spa

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: