CRL Round Clear View™ Mirror Defoggers can be positioned according to our customer's height requirements. Consider using two Defoggers when installing over counters with two basins. They are designed to be installed in new and retrofit applications that allow at least 3/16" (5 mm) space behind the mirror. The "hardwire" (non plug-in) connection ensures that the aesthetic integrity of your bath is not compromised. The adhesive surface of the Defogger is bonded directly to the back surface of the mirror. Installation is not difficult and conforms to standard industry practice. As with any electrical product, we recommend installation be performed by a qualified person, in accordance with local codes. Our mirror defogger's can be installed directly onto mirrors that require or have safety backing tape installed.