Antminer duct fan to 4 inches

To 3d print this model, I suggest 3 or 4 perimeters, no support, infill at your discretion and at least 300 microns of precisions.

Hello everyone!

This is my first upload on thingiverse. It is a fan duct dedicated to various application, but it's main purpose is to replace and/or extend a traditionnal 120mmx120mmx38mm fan to a 4 inches piping, such as a 4 inches blower fan, etc. It is designed to fit with the same screws used with the original fan, you won't need to replace them for a shor