DRF4432D20I is a low-cost sub-1 GHz transceiver module designed for operations in the unlicensed ISM (Industrial Scientific Medical) and LPRD bands. FSK (Frequency Shift Keying) modulation/demodulation multi-channel operation high bandwidth efficiency and anti-blocking performance make DRF4432D20I modules easy to realize the robust and reliable wireless link. The module can be configured to work in 40 channels with 1MHz channel space which reduces the interface from adjacent channels. It contains NetID which means only modules with the same NetID can communicate. The NodeID of modules can be different and it doesn't affect the normal use. The NodeID is reserved for the future function. DRF4432D20I integrates 256 bytes buffer. When the buffer is empty users can transfer 200 bytes data per time and even limitless data transfer can be achieved as long as RF data rate is lower than MCU data rate. The part name in the picture is DRF4432D20I-043L2 with RS485 interface module and operates at 3.4~5.5V with low standby current which makes it suitable for battery powered-up applications.