I've been using it fo r the iPhone 4S for the Navigon operation. This works very well. Sound is clear and loud enough. You have to make the sound settings in the Navigon app on default. Unfortunately, the quality of the microphone and the speakerphone is rather moderate. You have to speak loudly that the other one understands. Well, but that you can connect multiple iPhones, so I can use the speakerphone for my iphone 6 in the jacket pocket. While you can move the microphone as an extension cord is. Problem is if I change the vehicle.