Fitbit Inspire 2 Health & Fitness Tracker with a Free 1-Year Fitbit Premium Trial, 24/7 Heart Rate, Black/Black, One Size (S & L Bands Included)Earn Active Zone Minutes as you progress toward your weekly 150 minutes of heart-pumping activity and use 20 plus exercise modes to track goals like distance, calories burned and more.Operating temperature: 14° to 113°F