In 1969, Seiko released the worlds first automatic chronograph equipped with both vertical clutch and column wheel, known as the Seiko Speedtimer. Under a curved sapphire crystal glass is a vivid yellow dial, characteristic of the 6139 original, the second hand, and subdial minute hand at 6 oclock are in a bright red. With 12 spots of Lumibrite across each of the wide vintage-style indices, this Speedtimer is designed for legibility in dark conditions. In the style of the original, this piece has a blue and red aluminium bezel with a tachymeter feature and a chronometer second scale on the inside dial ring. The bracelet is tapered from the lugs all the way to the buckle. This modern version features a V192 solar chronograph calibre which charges in both natural and artificial light. Accurate to +/- 15 seconds per month, it has a power reserve of 6 months at full charge. Prospex is a combination of the words Professional and Specifications. Seiko Prospex timepieces are designed to be practical, reliable and durable; to meet the high standards required in extreme environments for sports lovers and adventure seekers alike.