Nautilus Strapless Heart Rate Monitor Strapless HRM, No Chest belt required Heart Rate, 30-240 BPM, Upper and Lower limit heart rate zones and % of maximum heart. Calorie burned 0-9999 and exercise timer ragen 99 hours, Time AM, PM hour, minute, second 12/24 hour format. Calendar: Month, date, day and year adjustment Dual time Time of Day and Calendar Countdown timer Resolution 1) second measuring range: 99 hours Electroluminescent backlight, Water resistant up to 50 meters, key beep ON/OFF.