Unlike the previous version of the Sonoff 4CHR2 switch, you have access to the "self-lock" (allows you to switch on devices that remain switched on until they are switched off manually), "interlock" (when you switch on the second device, the other is automatically switched off) and "tap" (when switched on, the device is switched off after a preset time) modes directly via the application on your phone. The self-locking mode enables the four connected light sources to be switched on and off immediately. Users can remotely control the connected devices via the free eWeLink application, available on iOS and Android platforms. Compatibility with Amazon Alexa, Amazon ECHO, Echo Dot, Amazon Tap, Google Assistant, Google Home, Google Nest and IFTTT also enables voice support and collaboration with smart assistants. The robust housing is made of high-quality, fire-resistant PC material, which offers excellent protection when using connected devices.