The Unicel 7Ch-975 hot tub filter with 1-1/2 inch course SAE threaded bottom is a compatible replacement for Dimension One Spas that use the OEM 1561-12 filter cartridge. Dimension One Spas have used several different filter sizes in their models and series over the years. Therefore it’s best to confirm that this Unicel cartridge is the same size with the same threads as the existing cartridge in your model to ensure proper fitment and performance.
 
Filter details: 
Unicel P/N no: 7CH-975
Diameter: 7"
Length: 10-1/2"
Top: Handle
Bottom: 1-1/2" SAE Thread (Coarse)
52 sq.ft.
Filter Media: Reemay
Brand: Unicel Premium
 
Also compatible replacement for:
Dimension One Spas OEM 1561-12
Pleatco PDO75P3
Filbur FC-0475