A generally cylindrical housing has proximal and distal ends and is formed with a length and a diameter. A cylindrical recess is formed in the proximal end. The cylindrical recess has an interior shoulder. A cone is formed at the distal end. An axial passageway extends though the cone. A hollow interior is in the housing forming a chamber in communication with the axial passageway. A cylindrical identifying component is positioned within the recess in contact with the shoulder. A marking component is positioned within the axial passageway and has an extent projecting distally of the distal end. A marking fluid is located within the chamber.
