Monoprice Mini E3D v6 clone Fan Duct with air holes

After installing a e3d v6 head in my MP Mini, I noticed the amount of space to let the air crossing the heatsink out the back was minimal. I could feel backwash from the fan so air was definitely not flowing unobstructed.

This is a remix of a 40mm fan duct, but I cannot find the original. I have printed many ducts but none fit the e3d v6 clone as well as this duct. The design is excellent and prints perfectly with no supports or anything.

So to allow more air to flow over the heatsink a