Blower guard for Prusa i3 for modified shroud

Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:2750512.

Simple part to put on blower fan. Original screws works as expected. Remix from : https://www.thingiverse.com/thing:1829733 Adapted for : https://www.thingiverse.com/thing:2578649 (duct_V2.stl)