For sale is a like new CST Laser L-Trac Trackball mouse with external switch. CST2545-5W-RC is model number for the mouse and CST-SButton1.2 for the additional switch.

This is an original model from Clearly Superior Technologies before they sold to P.I. Engineering, I had purchased a few spares back when they announced the change / before it switched to X-Keys. I don’t have the original box, it has been sitting in storage for years.