MSR Guardian Purifier Cartridge Replacement

Cabela's says:
Packed in a small plastic case, the MSR Guardian Portable Water Purifier Maintenance Kit is small enough to take into the field on long or short trips. Includes instructions, pressure-relief valve, relief-valve O-ring, piston O-ring, end-nut O-ring, piston-cup seal, umbrella valve, clean side cover, and MSR food-grade silicone lubricant. 3.25"L x 1.75"W x .75"H. Weight: 1.1 oz. Manufacturer model #: 2405. Small enough to take into the field Packed in a plastic caseKit includes: Instructions Pressure-relief valve Relief-valve O-ring Piston O-ring End-nut O-ring Piston-cup seal Umbrella valve Clean side cover MSR food-grade silicone lubricant