FIG. 1 is a front elevation view of a pen showing my new design, with a rear elevation view being a mirror image thereof;
FIG. 2 is an enlarged bottom plan view thereof;
FIG. 3 is an enlarged top plan view thereof; and,
FIG. 4 is a right side elevation view of the pen shown in FIG. 1, with a left side elevation view being a mirror image thereof.
The broken lines showing features on the bottom in FIG. 2 are included for the purpose of illustrating environment and form no part of the claimed design.