We claim the ornamental design for an end cap for an LED stick, as shown and described.
FIG. 1 is an isometric view of an end cap for an LED stick, showing my new design;
FIG. 2 is front elevation thereof;
FIG. 3 is rear elevation thereof;
FIG. 4 is a right elevation thereof;
FIG. 5 is a top plan view thereof; and,
FIG. 6 is a cross-sectional view thereof.
For each embodiment, the left elevation is a mirror image of the right elevation and the bottom plan view is the same as the top plan view, but rotated 180 degrees.