The sapphire crystal sections of the dial are treated with a special coating that blocks most of the visible spectrum of light. For the invisible UV light spectrum, however, the coating does not represent a barrier. Therefore, UV radiation can pass through to the luminous surfaces of the outsize date unhindered. This produces an interesting side effect: the date platform with its manually applied perlage, normally seen only by the watch- maker during the assembly process, is now visible to the owner as well. The small, overlapping circular graining produced by hand using a rotating abrasive peg is normally concealed underneath the dial.  Pretty cool, no?

Like all Grand Lange 1’s the Lumen will be 40.9mm in diameter, and this german silver movement consists of 400 parts.  The Grand Lange 1, despite not having the second barrel, has a power reserve of 72 hours.  As soon as we find out the price of these 100 limited edition watches, we’ll be sure to update you.