SONOFF DUALR3 Dual Relay Module Wifi DIY Switch Two Way Power Metering Description: DUALR3 is a flush-mounted Wi-Fi smart dual relay switch module that is installed behind any standard switch to transfer it into a smart switch for wireless remote control with mobile devices or voice command. Unifying your home appliances into an integrated wireless network to make them communicate with one another which is convenient for you to manage and control, including lights, home appliances and motorized facilities like roller shutters, window shades, blinds, awning, etc. .
eBay