Move to the beat with Fitbit Alta HRthe heart rate wristband that motivates you to reach your goals in style. Jumpstart your fitness journey with PurePulse heart rate and SmartTrack; automatic exercise recognition. Track your all-day activity and sleep, stay connected with smartphone notifications, and get friendly Reminders to Move. To download your size guide, simply open and save the PDF to your PC and follow the instructions on the document. Track steps, distance, calories burned and active minutes PurePulse heart rate monitor. Physical specification Size: large. Features Heart rate monitor.