The ornamental design for an earplug, as shown and described.
1. Ear plug
1.1 is a perspective view;
1.2 is a front view;
1.3 is a side view;
1.4 is side view;
1.5 is a top view;
1.6 is bottom view;
1.7 is perspective view; and
1.8 is rear view.
Ear plug used for stopping water from entering the ear, especially when surfing or performing water sports; the ear plug will keep water outside the ear and will simultaneously let air pass into the ear canal, hence permitting sound to be heard by the user when it is arranged into the ear.
In the drawings, the broken lines are for the purpose of illustrating environment only and form no part of the claimed design.