Description The Retro 51 Nikola Tesla rollerball is inspired by Tesla's spiral coil, and has concentric circles acid-etched into the barrel which are then copper plated, accented by platinum trim and clip. Each pen is packaged in a commemorative tube. Feel like you are rubbing shoulders with genius when you use this pen! Futurist, inventor, electrical and mechanical engineer, Nikola Tesla was a genius well ahead of his time. His inventions are still being used to this day and his theories were so advanced that they continue to be studied, experimented on and even power the modern world. Each pen comes loaded with a rollerball refill that flows with a medium line width.