Louis Erard Watch Excellence Chrono Moonphase 80231AA21.BDC51.  A love of craftsmanship in the finest Swiss tradition could well be Louis Erards motto. Or perhaps, quite simply, excellence. This quest for perfection, the technical and aesthetic maturity to which the Watchmaker aspires, Excellence. Time becomes an art of living, thinking, creating, with this elusive challenger at its heart. Guilloche dial.