Fitness Tracker – Activity Tracker with Heart Rate Monitor – Fitness Watch Waterproof Smart Watch with Step Counter… $8.39 – $10.91 Make sure this fits by entering your model number. 【 BUILT-IN USB PLUG 】 Fitness Tracker easy to charge with any USB block and computer; no charging cable and dock needed; one single charge gives you up to 7-10 days of working time. 【 MULTIFUNCTION HEALTH MANGER 】 24-hour heart rate monitoring and activity tracking and automatically tracks your sleep duration & consistency with a comprehensive analysis of sleep quality data, helping you adjust yourself for a healthier lifestyle. Press and hold the touch point to switch the screen interface.