In shades of anthracite and blue, this Endeavor Perpetual Calendar revisits H. Moser & Cie.’s emblematic complication in a visually striking manner. Combining tantalum, a stable and durable metal with a unique hue that’s exceedingly difficult to machine and polish with the ancestral technique of “grand feu” enamel ling, a new dimension of vibrant colors and textures embellish world’s most intuitive and legible perpetual calendar watch.