This is a 120 millimeter-4.5" square instrument fan. It comes with a finger guard. It runs on 12 volts DC 375 MA, moves 106 cfm of air, and is made by Papst-Motoren of Germany. The terminal conections are two flat pins on one corner of the frame. It has an aluminum frame and plastic blade. These fans sell for over $45.00. Here's a URL to a spec sheet.

http://www.alliedelec.com/catalog/catalogpages/85.pdf