The iMouse T30 incorporates the palm-grip design where each user can rest his entire hand over the mouse. The design encourages users to move their cursor by rotating the trackball with their thumb and reduces the need for hand movement. It is wire free by utilizing the 2.4 GHz radio frequency technology, offering a wireless range of up to 30 feet. It is also fully programmable, meaning that every mouse button can be customized to your preferred function with its programmable driver. With its 5 levels of DPI resolutions (400 -4800) the optical trackball provides superior accuracy with smooth motion reducing hand movement and space requirements. This mouse trackball is also easy to maintain - just push the trackball outward from its back, clean it and push it back in place. Its ergonomically contoured large size (1.25") completes its advantages making your daily computing tasks more comfortable and stress free.