As a benefit to the GN particles it vents throughout its hull, Ptolemy is invisible to all sensors. The particles would disrupt any nearby sensors and communications to quietly slip away from enemy detection. The only way to detect Ptolemy is through the use of wide-area sensor networks. Because the ship could only disrupt a limited area of space, a vast sensor network that was designed to notice blanks in movement patterns would clue off the enemy where Ptolemy is located. Even when intercepted, the enemy can only see Ptolemy in line-of-sight and can't get too close to Ptolemy or risk a series of electronic failures, especially communications. When forced into combat, Ptolemy can vent higher concentrations of particles to deploy its GN Field (relative to its particle reserves); however it's not an absolute defense as it can still suffer hull damage from close range enemy fire and beam attacks (relative to destructive yield). After enemy forces had figured out ways to counter the effects of GN particles, Sumeragi (commander of the ship) had Ptolemy enhanced with new offensive equipment: GN Arms and the Assault Container.