description:...easy to use in either hand and easy to install. The silver with black design fits elegantly with laptops. The compact size is easy to carry and storefeatures:- enhanced precision with optical engine- comfortable fit for either hand and for long-term usesystem requirements:- IBM PC Pentium 233 compatible or higher- Windows 98SE/ME/2000/XP/2003 & Mac OS 8.6 or higher- available USB portpackage content:- NetScroll 310specifications:- interface support: USB- system support Windows 98SE/ME/2000/XP/2003 & Mac OS 8.6 or higher- number of buttons: 3- Optical resolution: 800dpi- dimension: 100x90x40mm- gift box size: 170x90x40mm- body weight: 62g