The Logitech Marble Mouse T-BC21 is a vintage trackball mouse from 2002 that is still in working condition. It features a red ball instead of the typical trackball, and is connected via USB for easy setup. This wired mouse has a maximum DPI of 300 and includes programmable buttons for added functionality. Its ergonomic design and optical tracking method provide a comfortable and precise user experience. Made in China, this Logitech trackball mouse is a unique and reliable option for those looking for a classic input device.