must be touched for "naked" hard drives that serve as Archivtäger or external removable drives and by using the enclosure. That the touch of "naked" hard drives can be problematic if you are electrostatically charged, each should be known. By Cover the plate (and especially the sensitive electronics) on the one hand largely protected against electrostatic discharge voltage, on the other hand, the shape of the shell makes it easier to physical and especially non-slip stacking a plurality of plates in a cupboard / shelf to ensure the safe storage.
For anyone who filed his "naked" 3.5 "hard drives, a highly recommended accessory.