1,CE/FCC/ROHS certificate 2,supply:education,business 3,showed on 2011 GESS 4,will show on 2013 BETT 5,popular in schools Electric propertyWorking principleWireless electromagneticPower supplyUSB DC or 5V supplyPower consumptionDC 5V 100mAPC interfaceUSB 2.0/RS232Transmition speed12m/sUSB cable length20mPositioning accuracy≤0.5mmScanning speedStart dot 25ms, continious 8msCusor speed125 dot / ...