Crystal: Authentic Rolex uses synthetic sapphire — a premium rep should too. Mineral glass (common on cheap reps) scratches easily. Steel: Rolex uses corrosion-resistant premium steel; quality reps use heavy 316L stainless steel. Bezel & Ceramics: Ceramic bezels (e.g., Cerachrom style) resist scratches and age well — a sign of a better rep. Movement: The heart of a watch — au... https://repswatchhub.co.uk/brand/rolex/