This product is in excellent condition. It has been used in the past, but has very few signs of use.
The case is in good condition. It has some signs of use, but is still structurally sound.
An advanced business model, the HP-18C calculator has a "clamshell" design, opening like a book with two keyboards facing each other inside. It includes graphing and a date-time-alarm feature similar to a personal organizer. The 18C has 2K of memory.