The GMT hand on the NH34 is needs a larger diameter pushing tool than most commercial sets provide, with a diameter of around 2.5mm. This tool is very slightly oversized, allowing you to reliably fit a GMT hand to the NH34 movement.

Version 2 is 1.6mm. This works perfectly and avoids issues with pushing the GMT on too far. However, I found that my printer didn't manage the hole at all well and so I needed to drill it out with a 1.6mm hand drill.