by carefully, he means "virtually no touching allowed". attached to the top of the vortex generator, INSIDE of the electronics housing, Hopefully sealed off from the elements, is a mirror. if you put too much pressure on the generator, you could and probably will, fuck up the alignment of the mirror in relation to the optical emitter and receiver. which means... the emitter will probably still shoot photons at the mirror but the receiver probably wont see shit... and youll be Boned.