Useful when the plug is set

The concept sounds good: you can do with a car socket two, so that for example, the navigation system is running and you can charge your smartphone or tablet at the same time..
And the connector looks so nice from: The inclination of the connector can be set to latching steps, a red LED lights up during operation.
Of course the plastic material does not act as if you have a Nobel accessories manufacturer in his hand, but cheaper, stinking rubbish that's definitely not here.

So why the tide of negative reviews for this part?

Because - in my car - the plug is not easily clamps in the board socket, but simply fall out again.

But then what is this strange large knurled screw at the end of the plug? Screwing in the car can be such a part not.

The answer becomes clear if you look at the design in more detail: The thumbscrew can be four movable slats in the outer shell of the plug millimeter by millimeter move back and forth. These fins are forward wedge shaped and press, if you moved forward, the four clamping springs of the connector to the outside and thus increase the effective diameter of the quasi plug.

After appropriate adjustment of the connector is seated in my car now rock solid and the contact is not a problem because the front portion of the plug is - albeit very tightly - spring-mounted.

The two star deduction is available for
a) the fact that the user the purpose of the screw not simply mentioned a word;
b) the execution of the thread for this very thumbscrew: it is very fine and there is a danger that one overexcited it with repeated use.

Overall, therefore, a practical, usable product with considerable need for improvement in the guidance and the execution of the thread.