Case in steel with a delicately fluted caseband. Sapphire-crystal caseback. 42mm diameter. Bidirectional rotating bezel. Rounded lugs. Screw-locked crown. Water-resistant to 10 bar (100m).
Dial slate grey, signed Breguet. Hours chapter with luminescent Arabic numerals. Day/night indicator at 3 o’clock. 12-hour totalizer and date at 6 o’clock. Small seconds at 9 o’clock. Central minute totalizer. Luminescent hands and dots.
Self-winding chronograph movement, with “flyback” function. Numbered and signed Breguet. Cal. 584Q/2. 131/2 lignes, 26 jewels. 48 hours power reserve. Inverted in-line Swiss lever escapement with silicon pallets. Silicon balance-spring. Balance frequency 4Hz. Adjusted in 6 positions.
Strap in calfskin leather.


	Type XXI 3817 3817ST/X2/3ZU Description Case in steel with a delicately fluted caseband. Sapphire-crystal caseback. 42mm diameter. Bidirectional rotating bezel. Rounded lugs. Screw-locked crown. Water-resistant to 10 bar (100m). Dial slate grey, signed Breguet. Hours chapter with luminescent Arabic numerals. Day/night indicator at 3 o’clock. 12-hour totalizer and date at 6 o’clock. Small seconds at 9 o’clock. Central minute totalizer. Luminescent hands and dots. Self-winding chronograph movement, with “flyback” function. Numbered and signed Breguet. Cal. 584Q/2. 131/2 lignes, 26 jewels. 48 hours power reserve. Inverted in-line Swiss lever escapement with silicon pallets. Silicon balance-spring. Balance frequency 4Hz. Adjusted in 6 positions. Strap in calfskin leather.
Technical specifications
Mouvement Winding Self-winding Power reserve (hours) 48 Calibre 584 Q/2 Lines 13½ Jewels 26 Frequency 4 Balance-wheel Breguet Escapement Inverted straight-line lever Balance-spring Flat Oscillating weight 18 Carats Number of components 319	Case Metal Steel Skeleton No Sapphire caseback Yes Case shape Round Case width (mm) 42 Case thickness (mm) 15.2 Water-resistant (m) 100 Straps 3ZU
Breguet inventions Chronograph Self-winding

Type XXI 3817

3817ST/X2/3ZU

Description

Technical specifications

Mouvement

Case

Straps

Breguet inventions