High-precision trackball features a comfortable thumb-controlled design that is ideal for extended right-handed or left-handed use. Large trackball improves control while reducing hand and wrist motion. Fingertip control allows fast, accurate cursor movement. Marble optical technology delivers smooth, ultra-precise tracking. Customize buttons with included MouseWare software. WebWheel software optimizes Web browsing. PC and Mac compatible Trackman Wheel includes a USB to PS/2 adapter.