The installation is very simple, as long as one still far from being at the fan. With the normal self-tapping screws provided with the fan and you get also separately (the grid will be no screws!), Is screwed the grid on the fan. This works best with developed fan, otherwise it's a bit fiddly. Retrofitting at a difficult to access fan but nearly impossible. If the screws are tightened, the whole wobble-free and so silently. If the space but without grid already is scarce, one should remember that the grid again applying about 2 mm.
Clear recommendation for the grid!