What is this chuck?

[Haynie]

I am finishing going through the school auction stuff and found a chuck. It won't fit anything I have and there seems to be no way of opening it.

Brand: Northfield Precision
Ser No:35-135.

I can't find info on it on the net. Sorry, cell phone pic.

 

[GoatRider]

Got a side view? It probably opens with tommy bars.

 

[D.Oliver]

My guess would be an air chuck.

 

[Haynie]

No place for tommy bars.

What is an Air chuck?

 

[Majorbdk]

http://www.northfield.com/pdf/nfld_chuckcatalog.pdf

 

[Haynie]

Well, how about that. Wonder what a middle school shop was doing with something so precise? Guess I should have bid on those other pallets.