Minge clamps.

Asked the lighting guy what a 'Minge' clamp actually
does, as I've never heard of one. He took one look at my
puzzled face and started laughing so much he had to
show me with his hands.
Both of us were laughing our faces off in someone's
front garden with him wildly gesticulating when
the 'first' (first assistant, whose job it is to keep shoot on track
and very strict) shouted at us. I had to go and
sit behind a wall, and calm down, like a feeble-minded child.

But now I know what a Minge clamp does.
Not to be confused with a C*** grip, obviously.