Basic info. Video: Yes Type: Voting system Communication: Wireless Lcd screen: 31 x 30mm Frequency: 430~434mhz/2.4ghz Keys: 16 keys Size: 94 x 51.5 x 7mm Power supply: 1 pc cr2032 button battery Power: Rfmax transmitting power is 10dbm Antenna: Built-in antenna Weight: 25g (without battery) Export markets: Global Software: 100% integrated into microsoft powerpoint, easy to edit and follow your habits; more intuitively display of your topic. Supported functions: single/multiple choices\grading\scoring\right/wrong\ numeric question\rush answer...(contact us for more functions) Voting results displayed in real-time, report can be output and preserved permanently Diversified report forms help you analyze the research project from multiple perspectives Offer a variety of question types, so that your activities are more diversified and interesting Two-side response, distance could up to 100m. Powerful signal and no direction limited. 5kgs/pack