What is this that is missing from my throttle body?

[AceOfHearts]

After what i suspect were throttle position sensor issues, i bought a second hand throttle body to fit to my car to see if it sorts the problem. I have finally got round to doing the job today but the new throttle body i have has an extra part that is missing from the one i took off, but i am not sure what it is or if i need it

Here are the pictures of the part, it looks to be vacuum operated, maybe an auto choke thing? I cannot see any spare pipes in the area that look like they should be connected to it.

[SV8Predator]

As you haven't though to tell us what model or engine you have, It will be difficult for someone to give you an answer.

Is it from a 1956 2.4 litre model?

Or could it be the vacuum operated cruise control, which on (your, presumably)later model is electronically controlled?

It is from a Jaguar?

[AceOfHearts]

Yes sorry its a 1995 XJR, and it has been identified as a cruise control bellows assembly (which i dont have)