1. Long-distance wireless transmission (up to 500m in open area, 10kbps air data rate). 2. Operating frequency range: 433 - 458.5MHz, supports up to 255 communication channels. Maximum transmit power: 100mW (20dBm) with 10 adjustable power levels. 3. Built-in MCU; communicates with external devices via serial interface. Transmits up to 31 bytes per packet. 4. Supports one-to-one and one-to-many transparent transmission via ID configuration. Changing the serial port baud rate automatically adjusts the over-the-air data rate (10kbps to 100kbps). 5. Features a three-minute configuration window after power-on during which the module can enter AT command mode by sending 'AT+ENABLE=1' for parameter settings. After this period, the module operates only in data transmission mode and all commands are treated as regular data. 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 Open Area Transmission Distance: Up to 500 meters Dimensions (without antenna): 74 x 24 x 16mm Recommended for use with two or more units: - For 2 units: Module 1 and Module 2 can send data to each other. - For 3 or more units: One unit acts as master, others as slaves. Operates similarly to wired RS485 bus. Master sends data, all slaves receive. Any slave can transmit, allowing master and other slaves to receive. Only one device may transmit at a time. Applications: IP PTZ Camera Modbus temperature sensor LED Controller RS485 Relay modules Remote control and remote measurement systems Wireless meter reading Home automation Access control systems Smart metering Color: Blue Material: Plastic + Metal Package Contents: 2 x 433M-458M VHF/UHF Radio Modem RS485 Transceiver (With Shell) Note: Other accessories not included. Note: Lighting and display differences may cause slight color variation between image and actual item. Measurement tolerance: +/- 1-3cm.