This is a textbook for learning the basics of ultrasonic technology. (Compact Ultrasonic Series Vol. 6) I found this while organizing my textbooks from my student days. I flipped through it quickly, and it seems like there are no markings or writing. Due to rising shipping costs, it will be shipped via Yu-Yu Mercari Bin or Raku-Raku Mercari Bin with simple packaging. I am selling it at a low price, so please purchase it if you understand that it is a used item.