Wanted an easy to print, easy to install fan for the Maker Select Plus with the new metal electronics tray behind the print head.
Wanted high visibility (HV) and high clearance (HC). Gives over 270 degrees viewing angle of the extruder tip depending on your head level/other obstructions.
One hole fits over one of the existing lower screw holes for the tray holder for alignment purposes. The other hole requires you to remove the screw and replace it through the bracket. Might need a longer screw than the original. Don't remember if I had to replace it or not.
The 50x50x15 blower fan is secured by tension. No screws needed.
The whole fan duct installation only requires removing and replacing one screw.
Update: (Mar 4, 2018) - Added additional supports and a cross brace. When printed in PLA, the older versions would start to be attracted (sag) toward the heated bed and the nozzle.
Used supports for the screw hole bracket and the angled duct toward the fan. Only supports from the bed should be necessary.