Inogen one G3 Sieve replacement Columns are designed to use in Inogen One G3 Oxygen Concentrators. These replacement columns help in supplying pure oxygen from the surrounding air by removing nitrogen elements. These columns encompass sieve beds to transform normal air into medical grade oxygen. This filtered oxygen is vital for patients who require oxygen due to low oxygen levels in the blood. Low oxygen purity alert is issued 30-day prior to the time when the Replacement Column Pair needs to be changed and is indicated by “O2 Service Soon” on the LCD screen display.