Opened but used only about 3 times. The box is not included, but the operation has been confirmed and it works without any problems. The item is as shown in the photos. The following is quoted from the website: The "HRM-Pro Plus" is the successor to the "HRM-Pro". It is a heart rate sensor that is worn on the chest to obtain accurate, real-time heart rate data, which is necessary to take your performance to the next level. For product details, please see the following URL: https://www.garmin.co.jp/products/accessories/010-13118-10