HEMMI Hemmi Slide Rule Bamboo Slide Rule No. 2664S For General Use (Office/Technical) I found something nostalgic in the closet. In the 1970s, when I was in technical college, we didn't have calculators, so I used this to do calculations. I remembered using it for exams, including trigonometric functions and logarithmic calculations. It's unbelievable from today's perspective. Maybe it would be nice to use this sometimes and enjoy a retro feeling. The case has scratches and stains due to aging, but the main body is relatively clean with few scratches, and the slide moves smoothly. Please refrain from purchasing if you are nervous or concerned, as this is a used item.