The Longines Symphonette is an oval-shaped ladies wristwatch launched in 2015. It is available in four sizes: S (16*25mm), M (18.9*29.4mm), L (21.9*34mm), and XL (23.9*38.6mm).Reference L2.306.0.57.0 has L-size case with diamond-set bezel and a black dial.
