... and USB receiver. Function: 1, Laser pointer;2, Page up/down;3, SD card reader function for optional;Technical parameters: Others Feature ... delivery were guaranteed;3.System: Windows98, Se,Me,2000,XP, Mac OS, Linux,Windows Vista;4, Warranty period: 1 year;5 ... ; VSON have got ISO 9001 Approved in 2008 V-821 Wireless presenter with Laser pointer