Need help IDing an A/C component

[Prong]

Do any of you guys know the exact name of this part? I suspect it cuts off the outside air when the a/c is selected. It sits in the passenger side cowl area under the cowl screen. I need to replace it due to the fact that the "hinge" area that allows it to open/close as required has almost completely broken. It came off of my 79 K10 with the factory air. I found one number stamped on it which may be a GM number: 6262685 -A Any help on locating a replacement would be much appreciated as well.