The ornamental design for an attachmentdevice, as shown and described.
FIG. 1 is a perspective view of our attachment device.
FIG. 2 is a front elevation view of the attachment device of FIG. 1; the rear elevation view of the attachment device of FIG. 1 is a mirror image of FIG. 2.
FIG. 3 is a first side elevation view of the attachment device of FIG. 1.
FIG. 4 is a second side elevation view of the attachment device of FIG. 1.
FIG. 5 is a top elevation view of the attachment device of FIG. 1; and,
FIG. 6 is a bottom elevation view of the attachment device of FIG. 1; the adapter portion, which is shown in broken lines in FIG. 1-4, is not shown in FIG. 6.
The broken lines are included for the purpose of illustrating environment of use and portions of the structure that form no part of the claimed design.