Idea very well, weak implementation

I think the idea is still very good. However, there is an important drawback: The Bluetooth connection between the cap and Smartphone is not strong enough. She is constantly interrupted (not separated) when you carry the smartphone in the (winter) coat pocket. One would have the SP keep constantly in hand, which is not very beneficial. Another weak point is the headset microphone. Since it is located near the ear, so quite far away from the mouth, it is very quiet audible from the opposite. But since I have the hat, I use it, so 3 stars.