The Universal USB Dock Pro Flex is a mount for your iPhone that holds and charges the device while it’s in the car.
It serves to keep your iPhone charged while keeping it within easy reach on the mount.
Best is if you have some sort of Bluetooth integration, so that you can use the handset without having to hold hit, but can easily reach it without having to pick up the iPhone.
It’s also handy for keeping the screen within view. Sometimes when just keeping the iPhone in your car and someone calls, you can’t see who the incoming call is coming from, because it’s often (in my case) in a cup holder, or facedown (somehow it always ends up facedown).
You can take a closer look at it here.