Thread on the orange screw is M5x0.8 (right hand).
External thread on the pink nut is M8x1.25 (right hand).
External thread on the green knob is M14x1.5 (right hand).
The brown pin is for preventing rotation of the pink nut.
Turn the orange screw for rough adjustment: the orange screw moves 0.8 mm for 1 rev. of the screw.
Turn the green knob for fine adjustment: the orange screw moves 1.5 – 1.25 = 0.25 mm for 1 rev. of the knob.
It is possible to reduce this difference by choosing appropriate leads.