The Signo is a gel pen made by Uni-ball.
Pen modification purposes
Pen spinners use the metal tip from the Signo gel pen as a replacement for smaller, metal HGG tip in mods such as the RSVP MX. The metal tip is widely popular among pen spinners for its mild weight. Penspinners also use the caps in some mods such as the G2 Vortex.