Refueler
Well-known member
Oh dear, oh dear, it never occurred to me that anyone would take my post seriously, didn't you realise I was 'avin a larf?
I know perfectly well what they are for; and I do use them.
OK - so you are having a laugh ... but at least anyone else who had never seen one now has an idea what its for ...
Personally I still walk my dividers across a chart !!