Does anyone know what the "A" stands for at the end of a Smiths gauge number ?
Some gauges with an "A" are more common than those without.
The 'A' appears to indicate a later production run with some minor changes to the original specification, for instance, the Norton Commando
SSM 3001/02A speedo has the later Norton Villiers 'Green Globe' logo (and later cable fitting) instead of the original /02 solid green 'spot'.
The actual significance of the 'A', could depend on the actual variation. Nothing to do with anti-vibration as far as I'm aware.https://www.ebay.com/itm/144688887369