Technology: radio frequency Frequency: 433.92MHz Function includes: Laser pointers, change slide, mouse, PowerPoint display, blank screen Clock, Built-in timer, Second counter Built-in flash memory: 128, 256, 512MB, 1, 2 and 4GB USB plug-and-play, no driver required Operation system: Windows 98, 2000, ME, XP, Linux, Mac and VISTA Control distance: 10m Dimension: 12.3 x 3 x 1.4cm Patent number: ZL 2005 30073114.0 Certificate: CE and FCC approval, RoHS compliant