In-Wall No-Neutral Smart Dimmer with QuickFit and SimpleWire enhancements. No neutral wire required for installation! In addition, revolutionary QuickFit design features a housing depth that is up to 20 percent smaller than the previous Z-Wave models. This reduced size coupled with the elimination of heat taps provides a better fit in older style boxes and multi-gang configurations. SimpleWire technology allows line and load to automatically be configured with auto sensing line-load terminals. All of this is coupled with Z-Wave S2 and SmartStart allows for effortless installation while being safer than ever!