It is a convenient pen format and is quite like a felt tip to look at. Looking at other reviews I was unsure about the product but thought I would give it a go.
It found it does work very well. On light scratches where there is still the cars colour paint left it will cover the scratch and will disappear, if the scratch has gone through to Primer or Metal it will just make the scratch look darker, which it is fair enough it's not a touch up paint.
My tips would be give it a good shake, the nib has a pump/flow action and needs a few to get it going nicely