The ornamental design for a externalssdstoragedevice, as shown and described.
FIG. 1 is a front perspective view illustrating the whole shape of this design.
FIG. 2 is a front view of this design.
FIG. 3 is a rear view of this design.
FIG. 4 is a left side view of this design.
FIG. 5 is a right side view of this design.
FIG. 6 is a top plan view of this design.
FIG. 7 is a bottom plan view of this design; and,
FIG. 8 is a rear perspective view illustrating the whole shape of this design.
The broken lines are for illustrative purposes only and form no part of the claimed design.
The external SSD storage drive is shown with a symbolic break in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design.