MACguard (the "MAC" stands for Metered Automatic Cartridge). MACguard offers you the ultimate in protection by measuring the amount of water the unit has filtered and shutting down the system when its 500 gallon (1895 litres) capacity has been reached (about a year's worth of drinking water for an average family of four).

Without MACguard, filters can be overused and lose their filtration ability. MACguard ensures you and your family will never get a drop of unfiltered water.