ELECOM DEFT Wireless Trackball Mouse, specifically the M-DT2DRBK model, designed for index finger control. Here's some information about this product: Design & Ergonomics: It features an ergonomic design for comfortable, long-term use, reducing wrist movement and enhancing productivity. Connectivity: It connects wirelessly via a 2.4GHz USB receiver, offering a range of up to 32.8 ft (10 m). Features: It includes a 34mm trackball for precise control, adjustable DPI settings (500/1000/1500), 8 customizable buttons, and a scroll wheel with tilt function. Compatibility: It is compatible with Windows 10/8.1/7 and macOS X 10.12 or later. Tested working pre owned condition Questions? Leave a comment below!