1. Long-distance wireless transmission (up to 500 meters in open area, 10 kbps air data rate). 2. Operating frequency range: 433–458.5 MHz; up to 255 communication channels. Maximum transmit power: 100 mW (20 dBm); 10 adjustable power levels. 3. Built-in microcontroller unit (MCU); communicates with external devices via serial interface. Supports sending up to 31 bytes per transmission. 4. Supports one-to-one and one-to-many transparent transmission via configurable device ID. Serial port baud rate adjustment synchronously changes the over-the-air data rate (10 kbps to 100 kbps). 5. AT command mode is available for parameter configuration within the first three minutes after power-on. Send “AT+ENABLE=1” to enter AT mode. After three minutes, AT commands are no longer recognized and are treated as regular data. Product Name: VHF/UHF Radio Modem RS485 Wireless Transceiver, 20 dBm, 433 MHz Working Voltage: 4.5 V – 5.5 V Interface: RS485 (5 V, GND, A+, B−) Frequency: 433 MHz Transmit Power: −40 dBm to +20 dBm Receiver Sensitivity: −114 dBm Operating Temperature: −25 °C to +75 °C Transparent Transmission Baud Rates: 1200, 2400, 4800, 9600 (default), 19200 bps Open-Area Transmission Distance: 500 m Dimensions (without antenna): 74 × 24 × 16 mm Recommended minimum quantity: 2 pcs Usage Instructions (for ≥2 pcs): - For 2 pcs: Module 1 and Module 2 communicate bidirectionally. - For ≥3 pcs: One module acts as master, others as slaves. Operates similarly to a wired RS485 bus: the master transmits data received by all slaves; any slave may transmit, and the master plus other slaves will receive. Only one device (master or slave) may transmit at a time. Applications: - IP PTZ Cameras - Modbus temperature sensors - LED controllers - RS485 relays - Remote control and remote monitoring systems - Wireless meters - Home automation systems - Access control systems - Smart meters Color: Blue Material: Plastic + Metal Package Contents: - 2 × 433–458 MHz VHF/UHF Radio Modem RS485 Transceivers (with enclosure) Note: The package includes only the items listed above. Other accessories are not included. Color appearance may vary slightly due to lighting and display differences. Dimensional tolerance: ±1–3 cm.