I received and installed these - aside from having to pull pretty hard to stretch the center hole over the knurled Mavic sticks, they installed fine, and the tight fit should help to exclude dust. If you tear it, there are spares (4 in the box) which is good because the included "instructions" disclaim any warranty for that. The "instructions" are pretty funny mangled English and worth a look.
Don't bother pulling the stick-tape covering off before slipping over the sticks; it pulls off easily just before you press it down on the controller surface - recommend cleaning the controller with rubbing alcohol to help them adhere well.
I'd give them a thumbs-up so far, especially if you frequently fly in dusty areas.