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Uploaded on Apr 13, 2011
This is the fourth and final informational video of the weekly "Investment Opportunity" video series leading up to Portal 2's release, and narrated by Cave Johnson. Uploaded by Valve on their YouTube channel on April 12, 2011 (http://www.youtube.com/watch?v=wX9Sc8...), it showcases the Long Fall Boot, variant of the Advanced Knee Replacement.