... pens, ruler, protractor, set square, searchlight and other tools, and to page up/down, drag object, clone object, etc ... in addition to writing and drawing, it provides other practical function for classroom-teaching and business- presentation; ... 90% touch area: ±1mmTouch ModeFinger, pen, or any other non-transparent objectsTouch TimesUnlimitedInterfaceUSB interfacePower< 1W, < 200mAhTouch TypeSingle- ...