This is a CASIO stock calculator, the "KB-100". I am selling it because I no longer have a use for it. I have used it a few times, but there are no noticeable scratches or stains. It seemed to work normally before, but currently, the battery is dead, so its operation is unconfirmed. I will check the operation after purchasing a battery. It runs on a CR2016 battery. 【Brand】CASIO 【Condition】No noticeable scratches or stains 【Included Items】Instruction manual Thank you.