Replacement for Logitech Cordless Optical Trackman TrackBall
Original Trackball Replacement Ball For Logitech Cordless Optical Trackman T-rb22 - Mice & Keyboards Accessories - AliExpress
A size comparison between the Logitech Cordless Trackman Optical, the Microsoft Trackball Optical, and the Elecom Huge, for if anyone is curious. : r/Trackballs
Logitech Cordless Optical Trackman at TigerDirect.com