This solid 18K white gold Rolex Cosmograph Daytona is a Z series from circa 2006 1/2. It is a model number 116509 powered by a Rolex caliber 4130 automatic chronograph movement. This caliber is a Certified Chronometer with 44 jewels and 72 hour power reserve. This model looks like a steel Daytona from a distance, but on the wrist it has the heavy feel of a solid gold piece. It has the same 40mm diameter as the steel version, measuring about 43mm including the crown. At the time this video was made, this piece had a retail price of $30,700 USD. It was featured in the KeepTheTime watch store and has since been sold.