Honeywell Ademco 5818MNL Recessed Door Transmitter<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"> The 5818MNL is a magnetic contact sensor that provides concealed protection for doors or windows. </span></li><li><span class="a-list-item"> The 5800 Series of door and window transmitters provide the most reliable， convenient and cost effective solutions for security protection. These devices are powerful and versatile enough to help solve even the toughest， most labor intensive installa </span></li><li><span class="a-list-item"> With a demonstrated outdoor range of over a mile， the 5800 Series has the best performance of any transmitters available today. </span></li><li><span class="a-list-item"> Includes self-contained transmitter and reed sensor Virtually disappears once installed Easy replaceable AAA Lithium battery </span></li><li><span class="a-list-item"> 0.5 gap (transmitter to magnet) Features a tapered cylinder for easy and flush fit Dimensions: 0.75" diameter x 3.0" length </span></li></ul></div><img src="http://ecx.images-amazon.com/images/I/31nODujF18L.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/319wOUQ2yoL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/31UJ80182BL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/31nDWKIoibL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/41TRvUeBYGL.jpg" noproxy>