Longines Symphonette watches

The Longines Symphonette is a small watch made in four case sizes, S, M, L and XL, each under a sapphire crystal. The M measures 18.9 mm across, the L 21.9 mm and the XL 24.9 mm.

The steel watches come with a black dial, an ivory dial with Roman numerals, or a mother-of-pearl dial with or without Arabic numerals. The Diamond versions add diamond setting to the steel watch, and every combination comes on a strap or a bracelet. The M is also made in red gold, with or without diamonds, and as a two-tone steel and rose gold watch with a diamond-set bezel and a mother-of-pearl dial (L2.305.5.87.7).

The reference number spells out the watch. L2.304 is the S, L2.305 the M, L2.306 the L and L2.307 the XL. The next digit gives the case: 4 for plain steel, 0 for steel with diamonds, 8 and 9 for red gold without and with diamonds. Then comes the dial, 57 for black, 71 for Roman (81 on the red gold), 87 for mother of pearl and 83 for mother of pearl with Arabic numerals, and the last digit separates the strap (0) from the bracelet (6). The L2.306.0.87.6, for example, is the L in diamond-set steel with a mother-of-pearl dial on a bracelet.