All G2 (Galileo 2) kits are based around a custom-designed 9:1 MJF and Aluminum planetary gearbox, with a custom 9T stepper that features 20% higher surface area than the existing 10T designs (5mm tall spur gear vs 4mm tall spur gear) for increased wear protection and better power transfer from the stepper to the gearbox. The gearbox also follows the rules of planetary gearboxes, where the sun (spur) gear needs to be divisible by the number of planets for proper meshing and loading of the planets (3 planets, 9T spur).
G2 Extruder (G2E) is designed as a drop-in replacement for the CW2 extruder for Voron printers utilizing the Stealthburner toolhead. G2E features a custom large drive gear (16mm diameter) mated to an idler bearing to help prevent extruder artifacting due to gear meshing, and because it features a planetary gearbox, there's no issue with gear-meshing noise as found on CW2. G2E is also fully compatible with all current toolhead boards available.
G2 Standalone (G2SA) is designed as an Orbiter 2.0 or Sherpa Mini drop-in replacement extruder and utilizes the G2E kit parts for assembly. This expands the printer lineup for G2 to any printer compatible with the Orbiter 2.0 or Sherpa Mini, and gives the benefits noted above for G2E to every compatible printer. The G2SA is also a lightweight extruder, comparable to the Orbiter 2.0.