If your current RO system uses expensive proprietary filters, we recommend you convert your system to a PuROTwist Reverse Osmosis Water Filter System. This high quality conversion kit includes just the manifold and filters. You can keep your tank, faucet and lines installed in place. Simply remove your old system and plug the tubes into this new system. Later, to replace the filters for this system, simply twist the used filter off and twist the new filter on, at nearly half the price of your proprietary filters! No tools, no buckets, and no mess. The PT4000T50-SS-RK is a 4 stage, point-of-use RO system that treats water at 50 GPD.