The panorama of manually-wound Rolex Daytona chronographs encompasses seven different models, plus two bejeweled models made in extremely small numbers. Among the non-bejeweled timepieces, only three models truly qualify as having an Oyster case (indeed, while these three models bear the Oyster designation on the dial, the others do not). A true Oyster case is defined by the screw-down case back, screw down crown and screw down chronograph pushers, thus ensuring increased water resistance. Reference 6265 is indeed one of these highly sought-after models. Together with its sister reference 6263 (the difference being the black-insert bezel rather than the metal one), the reference 6265 is the final evolution of manually wound Daytona. It is defined, beyond its metal insert and screw-down pushers, by the caliber 727 (evolved from caliber 722-1).