Dual to single fan adapter 2x 40mm to 1x 80mm

This is fan adapter designed to convert dual 40mm fan mounting into single 80mm mounting. I've divided this item into two parts and printed this on prusa i3 printer with 0.3mm layer height setting using no supports. The effect was satisfactorily.

The project contains either STL mesh model and FCStd FreeCAD source file so you can easily fit this item for your requirements using FreeCAD open source software.