The ornamental design for a sliderknob, as shown and described.
FIG. 1 is a first perspective view of the slider knob according to the present invention;
FIG. 2 is a second perspective view thereof;
FIG. 3 is a first end view thereof;
FIG. 4 is a top view thereof;
FIG. 5 is a second end view thereof;
FIG. 6 is a bottom view thereof;
FIG. 7 is a first side view thereof;
FIG. 8 is a second side view thereof; and,
FIG. 9 is a perspective view showing the slider knob in its environment of use, wherein the dashed lines show environmental structure only and form no part of the claimed design.
The broken lines shown in the drawings are for illustrative purposes only and form no part of the claimed design.