1. Long-distance wireless transmission (up to 500m in open area, 10kbps air data rate). 2. Operating frequency range: 433–458.5MHz, 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 port. Transmits up to 31 bytes at a time. 4. Supports one-to-one and one-to-many transparent transmission via ID settings. Changing the serial port baud rate automatically adjusts the over-the-air data rate (10kbps–100kbps). 5. Features a three-minute configuration window after power-on during which the module can enter AT mode for parameter setting by sending 'AT+ENABLE=1'. After this period, the module operates only in data transmission mode and does not accept AT commands. 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 ground transmission distance: up to 500m Dimensions (without antenna): 74 x 24 x 16mm Recommended for use with two or more units: - For 2 pcs: Module 1 and Module 2 can send data to each other. - For 3 or more pcs: One unit acts as master, others as slaves. Operates similarly to wired RS485 bus. Master transmits, all slaves receive. Any slave can transmit, and the master plus other slaves will 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 Smart metering Color: Blue Material: Plastic + Metal Package Contents: 2 x 433M-458M VHF/UHF Radio Modem RS485 Transceiver (With shell) Note: Light and display differences may cause slight color variations. Measurement tolerance: ±1–3cm.