The Oyster Perpetual Explorer in Oystersteel features a distinctive black dial with characteristic 3, 6, and 9 numerals in Chromalight. Its highly legible hour markers, extremely resistant Oystersteel and waterproofness have made it a tool watch for exploration. The dial is the distinctive face of a Rolex watch, the feature most responsible for its identity and readability. The latest Explorer model’s characteristic 3, 6 and 9 numerals are now filled with a luminescent material emitting a long-lasting blue glow, like the hour markers and hands. Like all Rolex timepieces, the Explorer’s dial is designed and manufactured in-house, largely by hand to ensure perfection.