Do you know what this part is called?

[dgbaak]

I took the picture below of my 1996 Ford Explorer 6 cylinder engine compartment because I found a leak on a part but I'm not sure what it is, and can't seem to figure it out with my repair manual. If you know what the part is called that's circled in red on the linked picture below I'd love to know.
http://explorerengine.shutterfly.com/pictures/11
Thanks!

 

[Dan Whitaker]

That is your heater controll valve.

 

[dgbaak]

Thanks Dan!