The Garmin Vivofit 4 is an activity tracker with a 1+ year battery life . It tracks steps, distance and calories burned , monitors sleep and provides a personalised daily step goal . The Vivofit 4 is safe for swimming and showering and features an always-on colour display, so you can wear your tracker 24/7. Thanks to its 1+ year battery life, you can ditch the charging cord and stay on the go. The display is bright and easy to see, even in the sunlight , and you can customise the screen with colour themes, watch faces and text phrases. The Vivofit 4 features: Move IQ , which can automatically capture and classify different activities such as walking, running, biking, swimming and using an elliptical. That way, you don\u2019t need to manually start and stop your activity timer. It can even automatically start an activity timer for walks and runs. Garmin Connect compatibility, so you can save, review and share your captured data . You can easily compare today\u2019s totals or past results, or tap in for more detailed information. You can also get involved in social challenges. Move bar , which alerts you if you\u2019ve been stationary for too long . You can reset the bar by walking for a couple of minutes, inspiring you to get up and move. Daily step goal , which the Vivofit 4 assigns after learning your current activity level. As you meet your milestones, it will adjust your goal for the next day, gradually nudging you toward a healthier lifestyle. Toe-to-Toe Challenge , which allows you to wirelessly connect to your kid\u2019s nearby Vivofit Jr 2 or another Vivofit 4 to kick off an instant timed step competition . Once complete, you\u2019ll see your total number of steps during the one-on-one challenge and find out if you triumphed. Sleep monitor that captures data on your total sleep, periods of movement, and periods of restful sleep Trackers for total steps , calories burned , distance travelled and intensity minutes Weather widget Find My Phone Find more ways to beat yesterday with the easy-to-use Garmin Vivofit 4. It will encourage you into a healthier lifestyle in no time. SPECIFICATIONS Strap Material: Silicone or TPU Circumference [Small/Medium, Large]: 122-188mm, 148-215mm Weight [Small/Medium, Large]: 25g, 25.5g Thickness: 9.4mm Display Dimensions: 11 x 11mm (0.43 x 0.43 in.) Display Resolution: 88 x 88 pixels Display Type: Sunlight-visible, transflective, 8-colour MIP (memory-in-pixel) Water Rating: 5 ATM Battery: 2 x SR43 (user-replaceable) Battery Life: Up to 1 year Memory: 4 weeks of activity data Clock: Time/date, automatic daylight savings, alarm clock, timer, stopwatch Sensor: Accelerometer Activity Tracking: Step counter, move bar (displays on the device after a period of inactivity to encourage movement), sleep monitor (total sleep, as well as periods of movement and restful sleep), calories burned, distance travelled, intensity minutes, auto goal (learns your activity level and assigns and daily step goal) Compatibility: Bluetooth Smart and ANT+, iPhone and Android smartphones, Garmin Connect Mobile, Move IQ, TrueUp Other features: Weather, Find My Phone, Toe-to-Toe Challenges