HE635M:MS/pro, MS card reader HE636M:Mini-SD Card reader HE637M:T-flash card reader HE638M:XD card reader HE639M:SD card reader HE637A:Micro-SD,T-flash HE637B:Micro-SD,T-flash,MMC Micro 1.Support USB 2.0, backwards compliant with USB1.1 2.Support Micro SD, MMC Micro,Trans Flash 3.OS support: Windows, Mac& Linux 4.Driverless for windows ME/2000SP3/XP, Mac OS9.X,Linux2.4 or above