Supply voltage 3.2V - 5.5V. (If operating in continuous transmit mode for extended periods, it is recommended to use a 1N4007 diode in series when supply voltage exceeds 4.5V to prevent overheating of the module's built-in LDO) Default communication distance (open area test): approximately 600m (adjustable up to 1000m with air baud rate of 5000bps) Default idle current: 16mA (current varies depending on operating mode) Operating frequency range: 433-473.0MHz, up to 100 programmable channels. Maximum output power 100mW (configurable) Module supports firmware updates. Default factory settings: operating mode FU3, baud rate 9600bps, communication channel CH001 (433MHz) Color: Blue Material: Plastic Dimensions: 27.8 x 14.4 x 4mm Package Contents: 1 x Wireless Serial Port Module Only the above package content, other products are not included Note: Lighting and display differences may cause slight color variation between the image and actual item. Measurement error allowed within +/- 1-3cm