A vital tool for diagnosing fibre optic faults on cars with MOST bus fibre optic audio such as Mercedes vehicles since approximately 2004.

MOST fibre optic faults manifest themselves as the head unit turning off after about 10-15 seconds.

If you do not have Star Diagnosis you need to bypass each unit on the car's fibre optic bus until you find the faulty unit.

The tool consists of a 'male' MOST connector with a fibre optic loop and a female shell, which allows you to uncip the fibre from a control unit and plug easily into the loop to determine if that unit was the broken unit.