Ford RS Turbo Wastegate diaphram assembly.
I was clearing out the shed & found this. It originally belonged to my eldest son who was into hot hatches back in the day.
He gave me authority to sell it. I was told it was a serviceable spare part he bought when he was running a 1989 Escort RST.
When he sold the car he also got rid of other parts he had, but obviously this wastegate was left behind.