The file 'Air Intake For DIY Air Filter For A Laser Cutter 3D Printer Model' is (stl) file type, size is 149.9KB.
This is part of a DIY air filter for the K40 laser cutter. A detailed description can be found here:
http://wayofwood.com/diy-air-filter-for-the-laser-cutter
and the usage is explained in this video:
https://youtu.be/BTTTxA3fuNQ