The Unicel 4000 Series 4CH-940 delivers 40 sq. ft. of filtration surface area engineered to the exact OEM specifications of your Dimension One Spas filter housing. With 176 precision-pleated folds of 3 oz. Reemay 2033 polyester media, this cartridge maximizes dirt-holding capacity and maintains consistent water clarity between cleanings longer than standard media alternatives.
IMPORTANT: Verify Your Filter Quantity Before Ordering
Some Dimension One Spas models require two cartridges for a complete filter service. Replacing only one cartridge in a dual-filter system will result in unbalanced flow and reduced filtration efficiency. Check your spa’s owner manual or filter housing to confirm how many cartridges your model requires, then add the correct quantity to your cart.
Specifications
| Filter Area | 40 sq. ft. |
| Length | 15″ |
| Outer Diameter | 4 5/8″ |
| Top Inner Diameter | N/A |
| Bottom Inner Diameter | N/A |
| Material | 3 oz. Reemay 2033 |
| Pleat Count | 176 |
| Top Cap: semi-circular handle | Bottom Cap: 1-1/4″ SAE thread |
Fits into:
| OEM Brand | Product Name | Part Number | Notes |
| Dimension One Spas | 40 sq. ft. Top Load | 1561-13 | Replacement for Dimension One Spas. Verify quantity required for your specific model. |
(This is not an exhaustive list.)
