This is a 950 Platinum A. Lange & Sohne Datograph Up/Down Flyback, 405.035. It has an Alligator strap with a Platinum buckle, and a scratch resistant anti-reflective sapphire crystal. The exhibition sapphire case back is secured with 6 screws, and there is a platinum screwed-down fluted winding crown. The 41mm diameter solid case, curved lugs, and flat bezel are polished, and it has rectangular chronometer pushbuttons. The minute hand of the chronograph jumps in 1-minu te increments rather than moving continuously, allowing for a more accurate measuring of the Flyback/Timing function. The Flyback complication instantly restarts the chronograph with a single push of the button – it isn't necessary to stop, reset, and restart the stop-watch. There is a large double window date display at 12 o'clock, with a rectangular quick correction button located on the case edge at the 10 o'clock position. The dial is black with luminous inserts in the sword hands, polished applied baton and dot index hour markers, and a large polished central seconds hand. There is a white printed minute, seconds, and fractions of a second chapter ring, and a perimeter Tachymeter ring. There is a small seconds sub dial at 8 o'clock, a 30-minute totalizer sub dial is at the 4 o'clock position, and a small Up-Down (AUF/AB) power reserve indicator is at 6 o'clock. It comes with the COSC Swiss Chronometer certification, it has a 60-hour power reserve, and it's water resistant to 30 meters/100 feet. The 13mm thick case, dial, and movement are all signed. The mechanical manually winding A. Lange & Sohne caliber L 951.6 movement is rhodium plated with fausses cotes embellishment. It's constructed with 46 jewels, 451 components, a shock absorber mechanism, and a straight-line lever escapement. The mechanism oscillates at a frequency of 18,000 vph (3 Hz). The A. Lange & Söhne Datograph made its debut in 1999.