Check out this mint condition
Mouse Systems serial optical mechanical mouse, circa 1991. A MSC Model GM-301. This was a product often sold with PC PAINT, an excellent early DOS pixel paint program (runs great in DosBOX), rivalling Deluxe Paint, or superior.
PCPAINT ver. 3.0 is still unmatched for creating pixel art working at a the solid pixel level. Serial ports are pretty much gone from modern systems and laptops, however, serial mice can still be utilised via serial to USB adapters, which can be found on eBay. Mouse Systems, operating in the U.S. from Fremont, CA was eventually purchased by KYE.