1. Long-distance wireless transmission (up to 500m in open area, 10kbps air data rate). 2. Operating frequency range: 433–458.5MHz, with up to 255 selectable communication channels. Maximum transmit power: 100mW (20dBm), adjustable in 10 power levels. 3. Built-in MCU; communicates with external devices via serial interface. Transmits up to 31 bytes per packet. 4. Supports point-to-point and point-to-multipoint transparent transmission via ID configuration. Serial port baud rate changes automatically synchronize with over-the-air data rate (10kbps–100kbps). 5. Features a three-minute initialization window: within three minutes of power-on, the module can enter AT command mode by sending 'AT+ENABLE=1' for parameter configuration. After this period, AT mode is no longer accessible and all input is treated as data transmission. Product Name: VHF/UHF Radio Modem RS485 Wireless Transceiver 20DBM 433MHz Transmitter and Receiver Working Voltage: 4.5V–5.5V Interface: RS485 (5V, GND, A+, B-) Frequency: 433MHz Transmit Power: -40 to +20dBm Receiver Sensitivity: -114dBm Operating Temperature: -25°C to +75°C Transparent Transmission Baud Rates: 1200, 2400, 4800, 9600 (default), 19200 bps Open Area Transmission Distance: Up to 500 meters Dimensions (without antenna): 74 x 24 x 16mm Usage Instructions (requires 2 or more units): - For 2 units: Module 1 and Module 2 can send and receive data bidirectionally. - For 3 or more units: One unit acts as master, others as slaves. Operates similarly to wired RS485 bus. Master sends data to all slaves; any slave can send data back to master and other slaves. Only one device may transmit at a time to avoid collisions. Applications: IP PTZ Camera Modbus temperature sensor LED Controller RS485 Relay modules Remote control and remote monitoring systems Wireless meter reading Home automation systems Access control systems Smart metering Color: Blue Material: Plastic + Metal Package Contents: 2 x 433M-458M VHF/UHF Radio Modem RS485 Transceiver (With protective shell) Note: Other accessories are not included. Note: Lighting and display differences may cause slight color variation between image and actual item. Measurement tolerance: ±1–3cm.