This is a calculator from the 1970s. It features a distinctive green, 6-digit display using a Vacuum Fluorescent Display (VFD). It runs on four AA batteries. This item has been cleaned, both the case and the interior. Simple calculations have been performed, and it has been confirmed that all keys respond and calculate correctly. It is a specification that the numbers change erratically during calculation. The case has minor scratches and dirt, so please check the condition carefully in the photos. Currently, there are no problems with button operation or number display, but due to its age, the operation after shipping cannot be guaranteed. An AC adapter and batteries are not included. ※ The ruler in the photo is not included with the product.