Genius serial mouse, model GM-6000, vintage from 80-90ies | eBay
Vintage - Genius Netscroll + 2-Button Serial Ball Mouse with Scroll Button was listed for R400.00 on 18 May at 15:16 by ArxValdex in Naboomspruit (ID:586561336)
After 6 years I've updated my old but beloved Genius mouse : r/MouseReview