Its just like the rest of these video downloaders, which is said to be much better than they actually are.

This flat out said useless tool parts the videos in to small chunks of about 3.98 MB, which is about the same size as every single one of the rest of the useless video downloader add-ons i have tried for Firefox that also operates in such a completely useless way.

And no, its not because of the streams being stored that way on the server in small chuncks, they are actually stored on the tested streaming site as single files of about 2.4 GB size.
That was tested on a friends computer, where he tried using Firefox and IDM on that streaming site.