PRODUCT GRADING (Grade C) - Fair Condition > Visible scratches and signs of use throughout > Refurbished to the highest standards. Brown Box WHAT IS IN THE BOX Xiaomi Mi Smart Band 4 - Fitness Tracker PRODUCT DESCRIPTION The product is equipped with high density lithium polymer battery, which can achieve a light weight and up to 20 days of battery life. Upgrade 0.95\" Colour Screen More power-efficient OLED displays can display more information with less power. At a glance, you can tell the sender\'s name, number and information. Best for Running When you turn on active mode during activities such as running, you can measure GPS route, calorie expenditure, speed and heart rate in real time. Has the ability to analyse exercise data, recommended for daily health and exercise. Heart Rate Number Sleep Assist Function If you fall into deep sleep, your heart rate will drop. Heart rate sleep AIDS measure heart rate during sleep and more accurately measure light and deep sleep patterns. Does not support daytime sleep. Daily Steps Measurement Heart Rate Monitoring You can use a precise pedometer to measure the changes in your heart rate every day. Upgrade the step count algorithm. Count your steps correctly. You can monitor your heart rate 24 hours a day to see when it\'s in real time. PRODUCT INFORMATION Supported application - Fitness Tracker, Sleep Monitor, Phone, GPS, Pedometer, Heart Rate - Monitor Brand - Original Xiaomi Wireless communication standard - Bluetooth Connectivity technology - Bluetooth Operating system - Android Compatible devices - Smartphone Special feature - Sleep Monitor, GPS, Pedometer, Calorie Tracker, Heart Rate Monitor Human interface input - Touchscreen Screen size - 0.95 Inches Water resistance level - Waterproof