Mivatek Door/Window Sensor 4-pack (requires smart hub)<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"> Requires Smart Hub </span></li><li><span class="a-list-item"> Alerts you when a door or window is opened. </span></li><li><span class="a-list-item"> Use these sensors to protect your primary entry points and windows. </span></li></ul></div><img src="http://ecx.images-amazon.com/images/I/21OFZjR2fSL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/11eErbJ1hpL.jpg" noproxy>