Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:5804114.

the original version had the air intake on the fan facing the mount and restricting airflow. It also did not clear the rails properly and if your Z end stops are too tall (past the linear rail) it collides with it. This adapter clears both the rail and end stops just barely. I suggest a piece of double sided tape for in between the Bondtech and fan. As well as one at the union of fan and duct. This is OVERKILL as the fan is and extremely tight fit and should not require a screw etc. The tape is more of sealant and secondary mounting bracket.