Suunto Ambit3 Peak/Sport Smart Heart Rate Sensor<div style="text-align: left;"><strong>[Product Information]</strong><ul><li id="replacementPartsFitmentBullet" class="aok-hidden" data-doesntfitmessage="We're not sure this item fits your " data-fitsmessage="This fits your "><span class="a-list-item"><span id="replacementPartsFitmentBulletInner"><a href="#" class="a-link-normal hsx-rpp-fitment-focus">Enter your model number</a>to make sure this fits.</span></span></li><li><span class="a-list-item"> Real-time heart rate and calories burned </span></li><li><span class="a-list-item"> Compatible with Suunto Movescount App， sports apps for iPhone， Android， and Bluetooth Smart devices </span></li><li><span class="a-list-item"> Water resistant to 30m / 100ft </span></li><li><span class="a-list-item"> Adjustable strap length; minimum length 640mm， maximum length 940mm </span></li><li><span class="a-list-item"> Strap width 30mm </span></li></ul></div><img src="http://ecx.images-amazon.com/images/I/41fBFvDR9NL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/31Ks1SkaZBL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/51-mHIxlRSL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/21xA%2BCzNodL.jpg" noproxy>