A. Lange and Sohne 1815 Rattrapante Perpetual Calendar Platinum Watch 421.025FE Box Papers. Ultra-complex Manual winding movement combining a split-seconds (rattrapante) chronograph and a perpetual calendar with a moon phase. Complications & Functions Split-seconds chronograph: Measures split times and short intervals.Perpetual calendar: Automatically adjusts for month lengths and leap years. Displays: Analog date, day of the week, month, and moon-phase. Additional feature: Power-reserve indicator. Platinum round case 41.9 mm in diameter. Transparent exhibition sapphire crystal case back. A. Lange & Sohne on the fluted crown. Platinum bezel. Scratch resistant sapphire crystal. Argenté-Silver dial with blued alpha-style hands and black printed Arabic numeral hour markers. Top Subdial: Combines the date display with the moon-phase indicator at the 12 o'clock. Left Subdial: Day of the week alongside the split-seconds (rattrapante) minute counter at 9 o'clock. Right Subdial: Month alongside the leap-year indicator at 3 o'clock . Bottom Subdial: The small seconds dial combined with the power-reserve indicator at 6 o'clock. Black leather strap with a platinum deployant buckle. Excellent condition.