The Sonoff RM433R2 (NO BATTERY) with Remote Control is a 433.92 MHz 3V wireless receiver that operates in temperatures of -10°C to 40°C. It has a ultra low power design that can be remotely switched on/off by an RF signal, making it useful for home automation. The RM433R2 is designed for simple to use home automation, allowing you to control lamps and other electrical appliances from a distance. It is ideal for controlling home devices such as lights, curtains, doors, windows, fans, and pumps wirelessly and easily. It supports up to 16 remote controls and provides a secure control environment. The RM433R2 features an open source design, making it easy to integrate with third-party hardware and software. Additionally, the RM433R2 has over-the-air firmware update, allowing for remote control and software upgrades without opening the receiver.