Longines Equestrian watches

The Longines Equestrian is a family of small steel watches, 23 to 34 mm across, named for the sport Longines has been tied to since the late 19th century. After its 1878 chronograph calibre, the 20H, let the company make precise stopwatches, Longines began building its name in horse racing, and later in show jumping, endurance riding and eventing. It is official timekeeper of events such as the FEI Show Jumping World Cup, the Longines Global Champions Tour and the Kentucky Derby.

There are two lines. The Equestrian proper comes at 23.5, 26.5 and 30 mm; the Equestrian Horseshoe at 23, 26, 30 and 34 mm. Each is made in plain steel or as a Diamond version, with a black dial, a mother-of-pearl dial, or Arabic or Roman numerals. The Double Diamond is a mother-of-pearl Equestrian.

The reference tells them apart. After the model number, a 4 marks the plain steel watch and a 0 the Diamond version, so the L6.137.0.71.2 is the 30 mm Horseshoe with diamonds and Roman numerals, while the L6.131.4.87.2 is the 30 mm Equestrian in plain steel with mother of pearl.