Supply voltage 3.2V - 5.5V. (If you want to operate the module in launch state for a long time, it is recommended that when the supply voltage exceeds 4.5V, use a 1N4007 diode in series to avoid heating the module's built-in LDO) Default communication distance (open test): about 600m (adjustable to achieve maximum communication distance of 1000m, air baud rate 5000bps) Default idle current: 16mA (current varies in different operating modes) Operating frequency range: 433-473.0MHz, up to 100 communication channels. Maximum 100mW output power (configurable) Module supports software upgrades. Default factory settings: operating mode FU3, baud rate 9600bps, communication channel CH001 (433MHz) Color: Blue Material: Plastic Package Contents: 4 x Wireless Serial Port Module Only the above package content, other products are not included Note: Light reflection and different displays may cause the color of the item in the picture to be slightly different from the real thing. Measurement allowed error is +/- 1-3cm