GUNSON.Colortune looks like a sparking plug with a transparent chamber in place of the ceramic insulator. It allows you to see the colour of the flame in the combustion chamber of a petrol engine and, where it is possible, to adjust the mixture simply by colour.
Full instructions, more on applications and fault-finding included.
See Instructions as a PDF file. This Colortune has a 12mm thread and has a low volume chamber, mainly intended for motorcycles.
12-month Gunson warrantyE&OE