bed leveling knob with adjustment marks

Using G92 values to adjust the bed I felt the necessity to know how much I have to turn the knob. So, knowing the thread pitch of M4 and M3 screws (0.7 and 0.5 mm), I divided the circumference in 7 and 5 parts, between marks being aprox. 0.05mm .
Of course it is an aproximation but I had good result adjusting the bed under 0.1mm difference between center and corners in max 2-3 iterations. You have to lock the screws (I used a drop of superglue).
The files are for knobs of two diameters: 50mm and 30mm