What's it called?

I ordered a beer at Boomer's on the Hill a couple weeks ago and the bartender held the glass upside down over this hole below the taps.

She flipped a switch or pressed a button and a plume of ice cold water shot up inside of the glass, chilling it in seconds.

What's this thing called? How many bars around town have it? I've never seen it before.

(AP photo) 

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