This is an 18K rose gold A. Lange & Sohne 1815 Up & Down, reference 234.032. It has an alligator leather strap with an 18k rose gold tang buckle, and a scratch resistant sapphire crystal. There is a screw-down exhibition sapphire display case back secured with 6 screws. The 39mm diameter solid three-body case, downturned lugs, and rounded bezel are polished. The dial is matte silver with a stepped-down center, and with black painted radial Arabic numeral hour markers inside a railway-style minute chapter ring. It has blued steel epee hands, an up/down 72-hour power reserve indicator at the 8 o'clock posit ion, and a constant seconds subsidiary dial at 4 o'clock. The slightly recessed sub-dials have a fine concentric circle texture. It's water resistant to 30 meters/100 feet, and the 8mm thick case, dial, and movement are all signed. The mechanical manual winding A. Lange & Sohne caliber L051.2 movement has a ¾ back plate finely finished with a striped/ribbed finish and polished beveled edges. It's constructed with 29 jewels, 245 components, and a hand-engraved balance-cock, making each watch unique. The mechanism oscillates at a frequency of 21,600 vph (3 Hz). This A. Lange & Sohne 1815 Up & Down, reference 234.032, is named to commemorate the year watchmaker Ferdinand A. Lange was born, and for their novel 'up-and-down' power reserve indicator.