The Multi Fold Out Ruler from Midori is a simple, high-quality aluminum ruler.
It can be stored in a chest pocket or a pen case by folding it in half when not in use and 30 cm when in use. There is an angle notation on the central axis, and you can measure the angle every 15 degrees.
It is laser engraved so that the numbers do not disappear over time and use.
Made in Japan.
Also available in acrylic versions.