The ornamental design for a flashdisk, as shown and described.
FIG. 1 is a perspective view of a flash disk showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is a top view thereof, wherein the USB connector is sliding out showing the design in use.
The broken line showings of the USB connector are for the purpose of illustrating unclaimed portions of the flash disk and form no part of the claimed design.