The ornamental design for a wirelesskeyboard, as shown and described.
FIG. 1 is a perspective view of a wireless keyboard showing the claimed design;
FIG. 2 is a front view of the wireless keyboard showing the claimed design;
FIG. 3 is a rear view of the wireless keyboard showing the claimed design;
FIG. 4 is a left side view of the wireless keyboard showing the claimed design;
FIG. 5 is a right side view of the wireless keyboard showing the claimed design;
FIG. 6 is a top plan view of the wireless keyboard showing the claimed design; and,
FIG. 7 is a bottom plan view of the wireless keyboard showing the claimed design.
The broken lines in the figures show portions of the wireless keyboard which form no part of the claimed design, for example, but not limited to, characters, numbers and symbols on keycaps.