[Introduction]：E30-400M30S(4438) is a hardware module (SPI) based on the SI4438 RF chip imported from Silicon Labs. It is half-duplex, integrates transceiver and receiver, transparent transmission mode, SMD type, working frequency band is 425~525MHz, transmit power 1W , suitable for a variety of environments, using the SI4438 RF chip originally imported from the American Silicon Labs company, with high receiving sensitivity, strong anti-interference, and supports the development of low power consumption. It has been widely used in various industries, and has the characteristics of stable performance, long transmission distance, penetration and diffraction ability, etc.