This optional battery backup kit provides additional peace of mind for the Moen Smart Shower. MOEN shower changes showering forever with a cloud-based, app-driven shower. This next-generation digital Showering technology provides you with countless ways to create your ideal showering experience with the push of a button on the sleek controller or a tap of the app on your smartphone. Moen® Battery Backup Kit, For Use With: U by Moen™ S3104 4-Outlet Digital Thermostatic Shower Valve