Replacement Columns for Rove 6 and Inogen G5The replacement columns for the Inogen Rove 6 and Inogen One G5 are designed to keep your oxygen concentrator working at its best. These metal columns, sold as a pair, contain the sieve beds that filter out nitrogen, turning regular air into the high concentration oxygen you need. Over time, these sieve beds naturally wear out, which is why replacing them is essential to maintain optimal performance. Your device will alert you with a "replace columns"