The 3M Undersink Drinking Water Filtration System Replacement Cartridges filter potable municipal or well water to help provide cleaner, better tasting water by reducing common contaminants. 3M Purification, Inc., recommends a filter change interval of once every six months or sooner, depending on local water quality conditions.The 3M Undersink Drinking Water Filtration System Replacement Cartridges are designed for easy changing, with no spills and no mess, it is fast and sanitary requiring only 1/4 of a turn to remove the old and install the new. The systems built-in bypass valve makes turning off the water supply unnecessary and double O-ring seals help protect against leakage. The 3M Undersink Drinking Water Filtration System Replacement Cartridges are ready to use after a simple cartridge flush and require no pre-charge before consuming the filtered water.The 3M Undersink Drinking Water Filtration System Replacement Cartridges help reduce:-Chlorine taste and odor, particulate, lead, mercury, asbestos and cysts** (3MDW111 replacement for use in 3MDW101) -Particulate, lead, cysts and select VOCs,** chlorine taste and odor (3MDW211 replacement for use in 3MDW201) -Chloramine, MTBE, TTHM, asbestos, lead, chlorine taste and odor, cysts and VOCs** (3MDW311 replacement for use in 3MDW301)The 3M Undersink Drinking Water Filtration Systems and Replacement Cartridges install quickly and easily under the sink for cleaner, better tasting water straight from the existing supply line. Undersink water filtration is a great option for any household where drinking water quality issues are a concern. Now you can enjoy cleaner, better tasting water on demand for drinking, coffee, baby formula, cooking and cleaning with 3M Undersink Drinking Water Filtration Systems and Replacement Cartridges.*Surfaces that are in contact with water are FDA CFR-21 compliant.** See Performance Data Sheet for details and additional reduction claims.