Electronic Thermometer Manufacturer: Omron User-replaceable battery Battery: LR41 (available at 100-yen shops) Currently working, no need to replace the battery. I'm selling this because I'm elderly and have trouble hearing, making it difficult to hear the beeping sound indicating the measurement is complete. I've replaced it with a model that has a relatively louder sound. Of course, it has been disinfected with alcohol. In addition to the main unit, a case, instruction manual, and the original box (slightly torn) are included. I've added the following information in response to a question about the measurement time: I've added a photo of the instruction manual as the fourth image. It takes 3 to 6 minutes for the measurement completion buzzer to sound. It contains a microcomputer that analyzes the temperature rise and sounds the buzzer when it determines the temperature is nearly stable. So-called "1-minute thermometers" estimate the curve of the temperature rise and display the result based on an estimation. Both methods are practically fine, but the accuracy of the item for sale is higher. Please note that I will use reused and recycled materials for shipping. Thank you for your understanding.