451 Series Moon Dials

These 451 Series Moon Dials use a gear system with two metal discs, one light and one dark, rotating behind a cutout representing the moon. The disc positions align with the current moon phase, visible through the cutout. They are typically made of brass or silver for the discs and cutout, although other materials might be used. They are designed for accurate moon phase display for years with minimal adjustment. Some variations might show the moon’s age numerically or use different cutout shapes. Available in various styles and finishes to match different clock designs.

These are specifically 451 Series Moon Dials for Hermle clock movements.