The internal rigid arch system makes fitting the chain very intuitive: from the top to the bottom of the wheel.
The aluminium central bar is at the heart of the automatic tensionnig system: just open out the built-in pedal and press down with your foot to activate tensioning. The chain will automatically slip around the tyre as soon as the car moves off.
External release system: just press the red buttons on the aluminium bar and release the safety catch, and the chain comes away.