The ornamental design for a skinstapler, as shown and described.
FIG. 1 is a right side elevation view of one skin stapler showing our new design;
FIG. 2 is a left side elevation view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is a front elevation view thereof;
FIG. 6 is a rear elevation view thereof; and
FIG. 7 is a perspective view thereof;
FIG. 8 is a right side elevation view of another embodiment thereof, in a first position, showing my new design;
FIG. 9 is a left side elevation view thereof;
FIG. 10 is a top plan view thereof;
FIG. 11 is a bottom plan view thereof; and,
FIG. 12 is a perspective view thereof.
The dashed lines are included for the purpose of illustrating portions of the skin stapler that form no part of the claimed design. The dot-dash broken lines represent the bounds of the claimed design and form no part of the claimed design.