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 Package Includes: 1PC Wireless Transceiver 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.