Technical features of calibre DB2115V4 : Number of parts: 275 - Jewelling: 35 jewels - Diameter: 30 mm - Power reserve: 6 days, ensured by a self-regulating twin barre) - Specificities: Titanium balance wheel with white gold inserts, optimized for temperature differences and air penetration . De Bethune" balance-spring with flat terminal curve. Silicon escape wheel . Spherical moon-phase indication accurate to a degree of one lunar day every 122 years . Triple pare-chute shock-absorbing system . - Frequency: 28,800 vibrations per hour