1. Supply voltage 3.2V - 5.5V. (If you to work in the module launch state for a long time, it is recommended when the supply voltage exceeds 4.5V series with a 1N4007 diode, to avoid heating module built LDO)2. Default communication distance (open test): about 600m (adjustable to achieve the maximum communication distance of 1000m, the air rate 5000bps).3. The default idle current: 16MA (modules in different operating current of the different operating modes).4. Operating frequency range: 433-473.0MHz, up to 100 communication channels. Maximum 100mW transmit power (can be set)5. The module supports software upgrades. The default settings: operating mode FU3, rate 9600bps, communication channel CH001 (433M).colour:BlueMaterial:plasticsize:27.8 x 14.4 x 4mmPackage Contents:1 x Wireless Serial Port ModuleOnly the above package content, other are not included.Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.