Height adjustable Fan Duct for Prusa i3 (Zonestar 802Q)

On some prints with especially steep overhangs facing the backside of the printer, they deformed as the standart fan duct just cooled the front of the print. That solved it

P.S.: The model was created with FreeCAD, exported (STEP-File) and refined in Solidedge ST8 Academic Edition so the PAR-File probably cannot be opened with the commerdcial version - sry

P.S.:
Widddo made an excellent remix of it https://www.thingiverse.com/thing:1447040