1. Long-distance wireless transmission (up to 500 meters in open area, 10kbps baud rate in the air).2. Operating frequency range (433 - 458.5MHz, up to 255 communication channels). Maximum 100mW (20dBm) transmit power (10 levels of power can be set).3. Built-in MCU, use serial port to communicate with external devices. Send 31 bytes at a time.4. The module can support one-to-one, one-to-many transparent transmission communication through ID setting Changing the baud rate of a different serial port will synchronously change the rate at which data is sent over the air. (10kbps-100kbps)5. Set the "critical three minutes". The module can send and receive data normally within three minutes of power-on. You can send the AT command "AT+ENABLE=1" to make the module enter the AT command state for parameter setting. There is only this reserved word in these three minutes. After more than three minutes, you will not be able to enter the AT command mode, you can only send and receive data, " AT+ENABLE=1" will also be sent out as data, there are no reserved words at this time.Product Name: VHF/UHF Radio Modem RS485 Wireless Transceiver 20DBM 433mhz Transmitter and ReceiverWorking voltage: 4.5V-5.5V;Interface: RS485(5V GND A+ B-)Frequency: 433MHzTransmit power: -40~+20dBm;Receiver sensitivity: -114dBm;Operating temperature: -25℃~+75℃;Transparent transmission mode baud rate:1200 2400,4800,9600(Default),19200;Open ground Transmission distance: 500MSize(without antenna): 74x24x16mmApplication:IP PTZ CameraModbus modbus temperature sensorLED ControllerR4D3C32 N4D8B08 N4D8C12 RS485 RelayRemote control, remote measurement system;Wireless meter;Smart Home,Home Automation,Wiser Home;Access control;Smart meterIdentification system;Data collection;IT household appliance;Intelligence household appliance;Baby monitoring system;Thermometersize:74x24x16mmMaterial:Plastic + Metalcolour:bluePackage Contents:5 * 433M-458M VHF/UHF Radio Modem RS485 transceiverOnly the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.