SONOFF 4CHPROR3 are both 4-gang DIY Wi-Fi Smart Switches designed to give you the ability to integrate smart control into your existing home to enable a smart home. Each smart switch has 4 gangs that can be used to control lights and other home appliances at the same time in four areas of your home. 4CHPROR3 is designed with an additional function for RF control. The function is purposely adopted to make you turn on/off the device connected with 4CHPROR3 via the RM433 remote controller.The different in 3 working modes including self-locking, interlock and inching mode. The new improvement on 4CHPROR3 compared with 4CHPROR2 is for users to set these 3 working modes on eWeLink APP instead of the hardware itself, easier to operate. So you can enable self-locking mode to turn on/off 4 connected devices separately, interlock mode to turn on 1 connected device every time and turn off the rest of devices simultaneously and inching mode to turn on 1 connected device and then make it turn off automatically after a given time (0.5 - 3600s). For the device away from the switch, you can create a moveable space in virtue of a DIN rail to make them be connected. Simply activate devices through your voice when the switch works with Alexa and Google Home smart aistant.