Saint-Imier chronograph models are fitted with an L688.2 column-wheel movement developed and produced exclusively for Longines by ETA, the movement manufacturer that is Longines’s sister company within the Swatch Group. Cases are steel, steel and rose gold or, on certain models, rose gold alone, and come in two sizes: 39-mm and 41-mm diameter. The dials are silvered or in black, and have small seconds displays at 9 o’clock and a date window between 4 and 5 o’clock. The chronograph has a central sweep-seconds hand, a 30-minute counter at 3 o’clock and a 12-hour counter at 6 o’clock. These also come on black or brown alligator straps or on steel or steel-and-rose-gold bracelets with folding clasps.
The third model in the collection is the most complicated. It contains Caliber L707, another exclusive Longines movement from ETA that supports four retrograde functions (day of the week at 12 o’clock, date on the right-hand side of the dial, second time-zone with a 24-hour scale on the left-hand side of the dial and a small seconds at 6 o’clock) as well as a day/night display and moon-phase indication (directly below 12 o’clock and above 6 o’clock, respectively). The steel case is 44 mm in diameter; the dial is black or silvered. Each is mounted on a black or brown alligator strap or a steel bracelet.