The RFM23B-433-S1 is a Hope Microelectronics RF Sub-GHz wireless radio module. It is designed for use in low-power, short-range radio applications such as home and industrial automation, smart meters and home security systems. The module is certified according to European directives and complies with the ETSI EN 300-220, EN 300-328, EN 301-489-1 and EN 301-489-17 standards. It supports multiple operating modes, supports 2-way communication, and can transmit low-power data up to 400 meters in an open environment. The RFM23B-433-S1 is ultra low-power, ultra-low-cost, fully integrated and is capable of operating reliably and reliably in high interference environments.