This is a rather rare version of the Rolex Daytona with Zenith movement, reference 16520. It has the 225 bezel and fits correctly with the serial number range of L50xxxx. It also has the floating dial meaning the word Cosmograph is further away from the “officially certified”. Take a look at the pictures and you will see what I mean. This is a Mark 1 dial, and as far as I know has to be pretty much the rarest version of the steel Daytona with Zenith movement. I will shoot more pictures in the coming days.