rotring - No reserve price - Mechanical pencil

rOtring trio-pen, NOS. An offer in an auction for a high-quality multifunction writing instrument aimed at technical drawing, design, or writing.
​Unlike other standard multifunction pens that combine colored inks or a single mechanical pencil, this model stands out by integrating three different pencils into a single body ("3 Feinminenstifte in einem Halter / 3 pencils in one", as indicated on the side of the box).

Color and Finish: The main body has a very elegant matte black finish, characteristic of rOtring's technical designs.
Grip Area: It features a metallic grip section with a knurled texture (a rough-engraved surface) in black, designed to provide a firm hold and prevent fingers from slipping during precision strokes.
Distinctive Detail: At the very top of the body, just before the push mechanism, the iconic red ring (rOtring) stands out—the brand's global identity seal.
Clip: Includes a very sturdy chrome-plated metal clip for attaching to pockets or folders.

The Three Pencil Thicknesses
The device is designed to house three of the most standardized and commonly used pencil thicknesses in technical and line drawing:
0.3 mm: For extremely fine lines, meticulous details, or preliminary guides.
0.5 mm: The versatile standard thickness, ideal for both writing and mid-weight lines.
0.7 mm: For thicker lines, outlines, or quick shading.
## Operation (Gravity Selection Mechanism)
According to the illustrated instructions on the back of the box, the system works via a pendulum or gravity mechanism:
Selection: At the top end of the pen body, marks for the thicknesses (0.3, 0.5, 0.7) are printed. To activate a specific thickness, you must rotate the pencil lead so that the desired number points upward (toward you) and then press the top button.
Retraction: To store the lead or change thickness, press a small quick-release button (usually located next to the clip) or operate the mechanism so that the tip retracts safely back inside the body.
Reload: The illustration also shows that the textured front cone can be unscrewed to access the internal tubes and reload the corresponding leads.
It is a highly valued German engineering tool for its practicality, since it allows instant line-thickness changes without having to release the tool or carry three separate pencils.