DUO 16 G4 is an exclusive hearing system. The classic designpremium behind-the-ear hearing systems offer a wide range of individual hearing system adjustment options. The DUO G4 hearing systems can alternatively be operated with disposable or rechargeable batteries. They feature wireless functionality, so they can be wirelessly connected to other audio devices and operated by remote control. A smartphone app is available to allow wearers to conveniently adjust hearing programs and volume.