Doosl Wireless Presenter, RF 2.4GHz Powerpoint Clicker Presentation Remote Control Pen. wireless presenter specifications: transmitter technology: radio frequency frequency: 2.4ghz control distance: 100m class 3r max output: distance: >200m wavelength: 650nm battery: aaa*1 working voltage: 1.5v dimension: 139.2*18.2*19.7mm weight: 25g usb receiver operation system: windows 2003, xp, vista, windows 7/8, mac os, linux dimension: 21.95*13.8*7.15mm weight: 2g safety warning: be warned that 2.4ghz pointers are not toys; they should never under any circumstances be directed into people's eyes or at passing aircraft. the pointer is not a toy and should not to be used by anyone under 21 it is illegal to direct the beam at any flying objects, moving vehicles and any public or private structures a pointer should not be directed at people or animals a pointer can be dangerous if not used properly note: long press the "up" and "down" at the same time to switch prezi mode.