Good afternoon Chalice,

Thanks so much for your question.

The pin drive that you have has a transparent cog on it. It extends in 1 mm increments and extends fully at 8mm. Once you go past the 8th click it simply springs back to the original setting.

If you have any issues what so ever doing this give us a call on 1300 761179 and I will en devour to help you.

Have a great day.

Matthew Walsh.