PATEK PHILIPPE - 3970 EP. Very fine platinum and diamond set wristwatch, never worn and still sealed in its original plastic cover together with the additional solid case back and setting pin. Perpetual calendar, moon phase. With box and certificate. Perpetual calendar chronographs by Patek Philippe are considered among the most refined and elegant timepieces ever made. It was not until the platinum 3970, however, that a true "black tie" version of the models was created.