The iMouse T40 incorporates the claw-grip design where each user can rest his entire hand over the mouse. The trackball location allows users to move their cursor by rotating the trackball with their fingertips and reduces the need for hand movement. It is cable 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 (1.5") completes its advantages making your daily computing tasks more comfortable and stress free. Back and forward buttons provide extra convenience for web surfing. The on/off power switch maximizes your battery life. The stowable nano-receiver is tiny and covenient to plug into your laptop or tablet.