Home Master TM Standard Undersink Reverse Osmosis Water Filter System A Better RO System-innovative design solves the most common problems with traditional RO systems. Exceptional purification - remove up to 99% of chloramines, chemicals, heavy metals, solids, etc. Superior design - uses filters built into filter housing for quick and easy annual filter changes. Advanced long lasting filters 3,900 gallons or 1 year between filter changes. 5 year limited warranty, Made in the USA.