Modular Carriage Rear Fan Duct

Most of the fan ducts I've seen for use with Don1337's E3D V6 modular carriage have been of a circular or semicircular design that blocks visibility of and access to the nozzle from the front of the printer. They also mostly use friction fit to hold themselves into the blower, which means vibrations and gravity tend to work them loose over time, which can cause them to crash into your print.

This fan duct is secured to the left side of the carriage with two screws, keeping it from colliding