Glacier Bay HDGROF4 Premium Defense 6-Month Replacement Filters 2 Pack (Fits System HDGROS4) Fits Glacier Bay Premium Reverse Osmosis Drinking Water Filtration System HDGROS4 System reduces: sediment; chlorine taste and odor; cysts; lead; chemicals such as chromium 6, arsenic and radium; and dissolved solids 6 month filter life Encased, quarter turn 'no mess' filter changes No need to shutoff water supply when changing filters