At first glance, the new Lange 1 Moon Phase looks pretty similar to the previous version, but it’s a substantially different watch. Sitting underneath the dial is the new caliber L 121.3, a new moonphase caliber based on the movement powering the 2015 update to the Lange 1. It’s the 20th in-house movement by Lange to feature a moonphase complication and it’s composed of 438 parts, including 47 jewels and 8 screwed gold chatons. It has a 72-hour power reserve and is manually wound.

The big innovation here though is the new moonphase indicator. Down at five o’clock the moonphase is nested in the top half of the running seconds register, but it’s not just one simple disc. Instead, the solid gold moon rotates as you’d normally expect a moonphase indicator to do (this one’s accurate to one day every 122.6 years) but the sky disc in the back rotates on its own once every 24 hours. This means that during the day the moon sits against a bright blue ground and at night it is framed in dark blue with contrasting laser-cut stars dancing behind it.

The new Lange 1 Moon Phase is 38.5mm across and 10.2mm thick, and comes in three different configurations – white gold with black dial, pink gold with argenté dial, and platinum with rhodié dial. All feature luminous hour, minute, and power reserve hands, plus luminous markers for the hours and the power reserve indicators themselves. Fitting for a watch meant to be read at night.

In both white gold and pink gold the Lange 1 Moon Phase is priced at €39,500 (approximately $42,430 at time of publishing), while the platinum edition is priced at €52,000 (approximately $55,860). Official prices in U.S. Dollars will be announced at SIHH in a few weeks.