Staedtler 'Mars Frizion' precision compass.
Can be opened and closed quickly using the 2 buttons on the shafts and then finely adjusted using the central screw.
Both rods are structured. The maximum size of the circle is 320 millimetres, extending up to 580 millimetres.
Entirely made from brass with a matte nickel plating.
The compass comes in a case with a snap closure, containing: an extension - small lead pencil - universal screw terminal for pens and ink pens.
Staedtler - Precision Compass - B009FLWH5G