Grand seiko watch spring drive chrono each part used in the making of this spring drive chronograph calibre 9r86 series watch is made in house by grand seiko the timepiece comes with 9r86 spring drive calibre spring drive is special and unique instead of escapement mechanism seiko utilizes a regulator and a mechanical stem that stores energy the movement features 30 bearing jewels it is protected from the penetration of water and magnetic influences the sbgc005 comes with a 72 hour power