For most Apollo missions, the stowage lists show that each astronaut carried a Garland mechanical pencil.
According to Chris Spain’s excellent Space Flown Artifacts site, despite the worldwide fame of the Fisher Space Pen it is probably the humble Garland mechanical pencil that was the most heavily-used writing instrument on the Apollo missions.
In total, thirty-three of these Garland mechanical pencils were flown to the moon on board the Apollo lunar missions, and twelve of these pencils were carried to the lunar surface in the lunar modules.
This particular Garland mechanical pencil and its associated lanyard was used by Jim McDivitt during the Apollo 9 mission. You can see the lanyard from the pencil in McDivitt's shoulder pocket during the mission.