The Q-Series filter, manufactured by Omnipure, is an easy-to-install replacement cartridge that twists right into a permanent head.
Omnipure's TQ56-50FC encapsulated membrane is compatible with both PuROTwist 4000 and PuROTwist 3000 Reverse Osmosis systems or any system that uses Omnipure Q-Series filters. It comes with a built-in flow restrictor and check valve and is easy to install.
Filters may need to be replaced more often than indicated depending on incoming water contaminant levels and volume of water being treated.