Aprilaire 4010 Transformer<div style="text-align: left;"><strong>[Product Information]</strong><ul><li id="replacementPartsFitmentBullet" class="" 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"> Humidifier transformer for models 400， 550， 550a， 558， 560， 560a， 568， 600 </span></li><li><span class="a-list-item"> Connect leads to 110-volt current; the screw terminals will then provide 24 volts </span></li><li><span class="a-list-item"> 1 year manufacturer's limited warranty </span></li></ul></div><img src="http://ecx.images-amazon.com/images/I/51s3ItwWypL.jpg" noproxy>