I'm trying to find the name of a tool which finds angles..and no it is not a protractor. I'll describe the tool. You aim it at the top of something and then pull a trigger which lets an arrow contained in the tool to swing on a metre. When you release the trigger the arrow locks into place and points to an angle.
It name has 'metre' in it.
I've tried googling but it's hard to google something you don't know the name of.
Any help would be much appreciated.