Adesso iMouse T40 - Wireless Programmable Ergonomic Trackball Mouse - Optical - Wireless - Radio Frequency - 2.40 GHz - Black - USB - 4800 dpi - Trackball, Scroll Wheel - 7 Button(s) - Symmetrical

Adjustable DPI Switch - Adjustable cursor moving speed from 400 to 4800 DPI. Micro-switch - Equipped with its 10 million times lifecycle microswitch, the iMouse T30 provides durability and reliability for your needs. Removable Trackball - Allows for Easy Cleaning. Ergonomic Contour Design - Minimizes forearm muscles from twisting and pains from Carpal Tunnel Syndrome. Power On/Off Switch - Maximizes your battery life up to 6 months. Built-in 1.25in Large Trackball with Optical Sensor - Tracks accurately and precisely with less muscle movement for maximum comfort. Nano Receiver - Tiny and convenient to plug into to your laptop or tablet. Programmable Driver - Easy-to-use user interface allows for full customization within seconds. Back/Forward Buttons - Provides extra convenience for web surfing. Wireless Technology - Works up to 30 feet of wireless distance. Operates on 12 different channels, each with 65,536 different IDs.