Cleo Skribent Messograf Pen (No. 6927).
The coveted writing tool for engineers and gadgeteers. 4” exterior Vernier caliper (0.1 mm metric and 1/16” inch scale). Metric screw thread scale and a tire tread depth scale. You can even use it to write things down. Retractable ballpoint pen. Efficient. Sleek. Handsome. 6.1” W x 1” H x .6” D. Chrome-plated solid brass. Made in Germany.