Type:Wireless Quiz Voting System Function:Voting Simultaneous Interpretation:No Technology:2.4GHz digital RF two-way technology Transmission distance:> 100 meters (328 feet) Transmission angle:360 degree Power required:two 1.5 volt batteries Batteries Life:1-2 years for ordinary use Certificate:CE, FCC, RoHS Response type:Single choice, rush Support self-paced answering:yes button:7 Show More