30mm to 40mm fan adapter.
thingiverse
A compact solution that saves time and effort - a universal 30-40 mm fan adapter is all you need, especially when you already have a CAD design at hand with the free Open Source CAD program known as FreeCAD.
Download Model from thingiverse
With this file you will be able to print 30mm to 40mm fan adapter. with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on 30mm to 40mm fan adapter..