Fitbit Alta HR， Black， Small (US Version)<div style="text-align: left;"><strong>[Product Information]</strong><ul><li class="showHiddenFeatureBullets"><span class="a-list-item"> Get the power of continuous heart rate in Fitbit's slimmest design yet-all day， during workouts and beyond </span></li><li class="showHiddenFeatureBullets"><span class="a-list-item"> With heart rate， you can better measure calorie burn， and use zones (Fat Burn， Cardio， and Peak) to find the right workout intensity for your goals. </span></li><li class="showHiddenFeatureBullets"><span class="a-list-item"> With sleep stages powered by PurePulse heart rate， automatically track your time spent in light， deep and REM sleep and take steps toward a better night's rest. </span></li><li class="showHiddenFeatureBullets"><span class="a-list-item"> See how working out more can improve your health by comparing your resting heart rate trends to your activity. </span></li><li class="showHiddenFeatureBullets"><span class="a-list-item"> Automatically track your steps， distance， calories burned and active minutes with up to 7 days of battery life </span></li></ul></div><img src="http://ecx.images-amazon.com/images/I/3173VJRD5gL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/41Qsry8R4AL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/31OfR0M0NmL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/41TDpx05o6L.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/51pM%2BOOVenL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/51ylx7coPKL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/21LlmxUCtTS.png">