In fantastically crisp condition, this 'U' serial (1998) stainless steel 16520 "Zenith Daytona sports the prized black dial with bold "Fat Six" subs, and is one of the last Tritium models before Rolex switched to Luminova. Powered by the legendary automatic 4030 calibre movement (a modified Zenith El Primero), these 16520 models have proved one of the most exciting investments of the last 15 years, and it won't be long before they are cruising past the £30k mark.