A. Lange & Söhne L951.5

The L951.5 is a manual-winding in-house caliber from A. Lange & Söhne, introduced in 2012 and still in production. It belongs to the L9xx Datograph family and serves as the movement powering the Datograph Perpetual, combining a column-wheel chronograph with a perpetual calendar complication displaying date, day, month, leap year, and moon phase. The caliber is assembled and finished by hand at the manufacture's Glashütte workshops, adhering to the brand's tradition of German finishing standards including three-quarter plates, hand-engraved balance cocks, and blued steel screws. The Datograph Perpetual remains the primary watch model utilizing this movement.