... can be built-in flash memory (optional). Technology:Radio frequencyFuntions:Green laser pointer,page up and down,built in flash memory optional ... :uo to 1000mLaser output:<1mw(ClassII),<5mw(ClassIII).Laser wavelength:532nm.Material: brass+plastic.Dimension:16.5*1.5cm Battery:AAA* ... system: Windows98,Se,Me,2000,XP,MacOS,Linux,Vista. RC Green laser pointer