What is this?

[86-lxi]

And what does it do? Anyone know?
http://img153.imageshack.us/img153/6473/p4020298.th.jpg (http://img153.imageshack.us/i/p4020298.jpg/)

[Pico]

i think thats the idle boost ..I might be wrong.
I dont have that on my 89 so im not sure

[CAWB352]

That is your air conditioning idle boost. the small upper vacuum line runs over to a solenoid in the box and the larger lower line goes over to the air cleaner.