This is a straight line marker that is used with extra fine tip sharpies that goes from 1/4in to 1in marks. The sharpie will fit in the holder just like its lid and there is just enough of the tip sticking out for the part to sit flat to your work piece. 

Assembly is pretty easy, just install an M4 screw and your good to go. 

I use it at work so I can get a straight line for marking edge distance for rivet placement. 

PRINT SETTINGS

Material: PLA / PETG

Layer height: 0.2

Nozzle diameter: 0.4

Infill: 5-15%

Perimeters: 3

Support: NO

This is my first model so I am open to any feedback and constructive criticism so that I can work on getting better.  Thank you for looking.