With an elongated body and smooth optical trackball technology, this mouse provides maximum comfort. This Off-table design consolidates fashion and technology and a new way to control mouse. No limitation of space. Fingertip-based controls allow for quick and accurate movements. Main Features: 100%new brand; Ergonomic Design; Off-table, for free and comfortable operation; Can be operated in various ways, avoiding harm to palm joint or muscle. High accuracy and sensation; Can bu used on the surface as same as optical mouse. User doesn't have to sit close to the monitor by using this track mouse; Avoiding eye fatigue and radiation harm. Can control the cross coordinates sensitively, simply with the thumb. Compatible with windows 2000/XP/Vista/Mac OS X. Resolution: Table 1200dpi, trackball 1600dpi; Dimension: 12cm*6cm*4cm; Length: 2m Shipping details: Color box or Blaster packing Quantity/carton: 40PCS Gross Weight: 6.5 kilogram Net Weight: 6kilogram Cu. Meter: 46x31x31cm or 56x23.5x45cm