Rado V10K, the hardest watch in the world. Curved scratchproof sapphire crystal, with an engraved Rado logo, metallized and soldered Case (top and sides) in scratchproofhigh-tech Diamond Ultra-precise Swiss quartz crownless movement. Water-resistant. Rt for 10,000 Vickers, scale of hardness used particularly in material technology. 10,000 Vickers is the ultimate value that only diamonds attain