Grand seiko watch spring drive divers sbge015j the grand seiko watch is a divers watch that comes with a number of useful functionalities and seikos spring drive technology this timepiece is equipped with 9r65 calibre that utilizes elegantly the spring drive it features a 72 hour power reserve the case is both water and magnetic resistant a power reserve indicator is available for the convenience of the wearer hands and markers are luminous for visibility in even the toughest of conditions