One of the most notable introductions from Breguet at Baselworld this year was the Classique Tourbillon Extra-Thin Automatic 5377. Available in a 42 mm diameter 18K rose gold or platinum case that measures a mere 7 mm thick. The 5377 Extra-Thin is currently the world’s thinnest tourbillon.
The dial is in 18K gold and is silvered as well as engine-turned in four different patterns. The tourbillon, which rotates once every minute and displays small seconds, sits off-center at 5 o’clock. Positioned asymmetrically, the frosted chapter ring has Roman numeral hour markers, with minute dots on the outermost part of the ring.
The hour and minute hands are open tipped Breguet style in polished stainless steel which has been blued. A power reserve indicator, which indicates from 0-90 hours via a straight blued hand, is located in between 8 and 9 ‘clock. Each piece is individually numbered and signed Breguet.
“Four engine-turned patterns demonstrate the fine workmanship with a hobnail pattern for the hours and minutes chapter, a barleycorn surround, a straight chevron pattern for the power-reserve indicator at 8 o’clock, and cross-hatching to outline each feature. A blue sapphire crowns the center of the tourbillon bridge to draw the eye down from the hands.”
The new caliber 581DR movement is a mere 2.97 mm thick. It features a platinum monobloc micro-rotor, 42 jewels, and it beats at a frequency of 4Hz (which is a high frequency for a tourbillon). It has been adjusted in six positions. The tourbillon carriage and the balance are in titanium. The balance spring is made of silicon and the escapement is in silicon and anti-magnetic steel.
A patented “high-energy” barrel provides an impressive 90-hour power reserve. “This new movement, protected by two patents, has been made into a work of art; the fine engraving and superb workmanship can be admired through the sapphire-crystal caseback.”
The case features a finely fluted case band with welded lugs and a leather strap with a triple-blade folding clasp. The water-resistance rating is 30 meters. (Ref. 5377BR/12/9WU – rose gold, 5377/PT/12/9WU – platinum)