Unicel 6CH-402 Spa Filter Cartridge – 40 sq. ft. | Master Spas Twilight Series | 2" MPT

The Unicel 6CH-402 is a 40 square foot replacement filter cartridge designed for Master Spas Twilight Series Eco-Pur filtration systems. Constructed with 3 oz. Reemay 2033 spunbond polyester media and 204 precision pleats, this top-load spa cartridge delivers consistent water clarity and extended service cycles. The semi-circular handle top and 2" MPT threaded bottom provide a secure, tool-free installation in compatible filter housings.

⚠️ IMPORTANT: Remove the Black Standpipe Before Installing
On Master Spas Eco-Pur filtration systems, an internal black standpipe is located inside the filter housing. You must unscrew and remove this standpipe before inserting the 6CH-402. Leaving it in place will prevent the cartridge from seating correctly and may restrict water flow. Refer to your spa owner's manual or contact a qualified technician if you are unsure of the procedure. Note: switching from the OEM Eco-Pur dual-cartridge assembly to a single-cartridge replacement may affect your Master Spas manufacturer warranty — verify with Master Spas before proceeding.

Specifications

Filter Area	40 sq. ft.
Length	9 1/2"
Outer Diameter	6"
Top Inner Diameter	Closed — semi-circular handle (no open bore)
Bottom Inner Diameter	2" MPT male thread (no open bore)
Material	3 oz. Reemay 2033
Pleat Count	204
Top Cap: semi-circular handle	Bottom Cap: 2" male thread/MPT

Fits into:

(This is not an exhaustive list. Verify compatibility before purchasing.)

Pro Tip: Confirm fit by measuring your existing cartridge — 9 1/2" length and 6" outer diameter. The 204-pleat construction provides greater filtration surface area for extended service cycles between cleanings.