Inogen One G2 G3 Output Filter Kit RP-107 by Inogen - BRAND NEW Product Specifications Product Features Fits Inogen G1, G2. G3 and Inogen at Home units Includes two filters and wrench Easy to insert Manufacturer Inogen Return Policy Unopened unused products may be returned for a refund, although we will be taking a 20% restocking fee. They must be returned at the customer's expense in their original packaging and meet the following conditions: Product must be in new condition. Product can't be opened or used Product must be returned in its original packaging. All Health and Personal Care items that come in contact with the body can't be returned if they have been opened