The MX Master 2S has since been followed up by the MX Master 3 and MX Master 3S. Identification The Logitech MX Master 2S can be identified by the model number ("M/N") M-R0066 (or part numbers, "P/N") 910-005131, 910-005139, 910-005839, 910-005965 depending on region, vendor,...