The MF-180 features simultaneous display of heart rate and % of maximum heart rate calories burned during exercise stopwatch with simultaneous display of heart rate automatic calculation of % of maximum heart rate (after entry of a profile; age weight and sex) out-of-zone alarm * Lap mode * No chest belt required * Includes 2 CR2032 Batteries * Electro-Luminescent back light * 1 Year Warranty Shipping Carton Size: 12 L x 10 W x 6 H