A size comparison between the Logitech Cordless Trackman Optical, the Microsoft Trackball Optical, and the Elecom Huge, for if anyone is curious. : r/Trackballs
Amazon.com: NEW Cordless Optical TrackMan (Input Devices-Wireless) : Electronics
New Original Mouse Replacement Ball for Logitech Cordless Optical Trackman T-RB22 Gaming Mouse - AliExpress