Once you39re out of the water including when the torso is lifted out of the water mid session real time heart rate interval summaries and stored heart rate are transmitted to your garmin multisport watch physical specifications unit dimensions lxwxd 580 1450 x 38 x 12 cm weight 72 g module size 294 x 514 x 85 mm module weight 51 g size adjustment bi fold sizing range 580 1450 cm battery cr2032 battery life 18 months swimming 3 hours per week water rating 5 atm ad