Features: Long-distance wireless transmission (up to 1000 meters in open space, Bit rate 1.76~62.5Kb/s); Working frequency: 410~512MHz for 433 version, 854.5~931MHz for 868 version, up to 256 communication channels; Maximum 156mW (22dBm) transmit power (10 levels of power can be set); Built-in MCU, use serial port to communicate with external devices; Send a maximum of 250 bytes at a time, and a maximum of 240 bytes in encrypted; The module can support one-to-one, one-to-many transparent transmission communication through setting. The receiving module can be set to Repeater to extend the communication distance (solder the M0 solder on the module); The module can set data encrypted transmission to enhances data confidentiality. Specifications: Working voltage: 5V-12V Interface : RS485 Frequency: 433M , 868M(optional) Transmit power: -9~+22dBm Receiver sensitivity: -129dBm Operating temperature: -25~+75 Transparent transmission baud rate :1200 2400,4800,9600(Default),19200,38400,57600,115200; Open ground Transmission distance : 1000M Size(without antenna): 45x30x14mm Weight(without antenna):12g Note: Please allow 0-1cm error due to manual measurement. make sure not mind before bid. Due to the differenceS between different monitors, the picture may not reflect the actual of the item. Package includes: 1PC Wireless Transceiver