Product: ・Introduction to Feedback Control, Corona Publishing About the product condition: ・The cover shows signs of use (scratches and dirt), but the inside is relatively clean. I didn't see any writing, but there might be something I missed. ・Please refrain from purchasing if you are concerned about the above. About shipping and packaging: ・We plan to ship via Yu-Yu Mercari or Raku-Raku Mercari. ・We plan to package the item in a bag to prevent water damage. ・If you have any preferred shipping or packaging methods, please consult with us before purchasing. Other: ・Please purchase only if you understand the above. ・Please feel free to ask if you have any questions.