This is a Ricoh calculator, likely from the 1970s. It features round buttons and a red LED display. The case has been cleaned, and the internal rechargeable battery has been replaced. Basic calculations have been performed, and the buttons and display are confirmed to be working correctly. The display may occasionally malfunction depending on the timing of the power switch operation. If this happens, please turn the power off and on again. The original charger (AC adapter) is included. The charger does not have a function to stop charging completely, so please avoid charging for extended periods (over 12 hours). The main unit has minor scratches, dirt, and paint peeling. Please check the photos for the appearance. *The ruler in the photo is not included with the product.