The Mobius TG uses its own needle — this one. It's the straight, matched partner to the TG's 0.5mm nozzle, ground to seat dead-centre in the tip so paint is metered cleanly instead of dribbling or spitting. With the TG built for high paint volume, the needle has to hold a precise taper along its whole length, and that's what keeps the Fan Cap spraying wide and even rather than streaky.
The needle slides out through the front of the airbrush for cleaning and swaps back in without tools, so a bent tip or a stubborn clog never ends a session. Keeping a spare is cheap insurance on a coverage gun you rely on.