A very special and rather unique piece in the collection, the Grand Lange 1 Luna Mundi is A. Lange & Söhne’s first two-watch set. Launched at the same time as the classic Grand Lange 1, it shares its size with this model but relies on the base movement of the first-generation Lange 1 Moon Phase, with its moon indication inside the small seconds. Just like the first generation Grand Lange 1, the adaptation of a smaller movement can be seen with the overlapping functions. Depending on the model, the Grand Lange 1 Luna Mundi correctly displays the moon phases clockwise for the northern hemisphere (white gold) and anti-clockwise for the southern hemisphere (pink gold). There are two calibre versions: the L901.8 for the northern and the L901.7 for the southern hemisphere. In the latter, an additional wheel reverses the sense of rotation of the lunar disc. Released in white gold and in pink gold as a set comprising the two timepieces, the model was only produced once with a batch of 101 sets. The dials are adorned with a representation of a celestial object – Ursa Major for the white gold model, Southern Cross for the pink gold version. A rare edition that proceeds the 2014 Grand Lange 1 Moon Phase.