About this 3D model

Inspired by http://www.thingiverse.com/thing:4839. Larger. Made for air. Quite noisy while running, but does blow :-) One of the fan cases has an error so that there's a hole on the bottom. I think http://www.thingiverse.com/thing:7337 is a derivative that fixes this. (Thanks, Moleofproduction).