garmin venu 4 41mm slate black gps smartwatch training wearable heart rate stress track workout suggestions training readiness mixed sessionsDesigned to support your goals, the Venu 4 GPS smartwatch is purpose built with advanced features to help you better understand your body and promote a healthier lifestyle. And with up to 10 days of battery life on the 41 mm model and up to 12 days on the 45 mm model, get a more complete picture of your health.