Kensington Expert Mouse - Wireless Ergonomic TrackBall Mouse for PC, Mac and Windows with Ambidextrous Design, Optical Tracking, Scroll Ring & 55 mm Ball – Red (K72359WW) : Amazon.co.uk: Computers & Accessories
KensingtonWorks Button4 & 5 (like old TrackballWorks) : r/Trackballs
Kensington Pro Fit Ergo TB550 Trackball Review | PCMag
Kensington Orbit Mouse - Wireless Mobile & Compact Ergonomic TrackBall Mouse for PC, Mac and Windows with Touch Scrolling, Ambidextrous Design and Optical Tracking - Red (K72352EU) : Amazon.co.uk: Computers & Accessories
K75326 Support Page | Kensington
KensingtonWorks™ Software Provides Personalized Mouse and Trackball Performance | Kensington
Mouse Or Trackball In The Studio | Production Expert