GU32768710, 641541, 643090, 1D001138 are superceding part numbers. This switch has a 10mm diameter threaded section with a 1.00 thread pitch. Uses 10mm crush washer part number 10528900, not included.
Fits these models: Breva 750, V7 Classic, V7 Cafe, Nevada Classic 750 IE, V7 Racer, V7 Stone, V7 Special, V7 Racer II, V7 Stone II, V7 Special II, V7 Stornello II, V7 Racer III, V7 Stone III, V7 Special III, V7 Anniversario III, V9 Roamer, V9 Bobber, 2015 and later Griso 8V, 2011 and later Stelvio NTX, California 1400 Custom and Touring, California 1400 Eldorado, Audace, MGX21.
This switch also fits numerous Vespa, Aprilia and Piaggio models.