SEIKO SPEED TIMER 5 SPORTS (TRIPLE HINGED) FIRST GENERATION.A RARE MEN'S STAINLESS STEEL AUTOMATIC DAY-DATE CHRONOGRAPH. Model: Speed Timer 5 SportsCase reference: 6139-6010Date: Circa 1969Movement: Signed, automatic, 21-Jewels, Cal.6139ADial: Signed, electric blue, applied squared luminous hour markers, silvered stick hands with luminous insert, red centre seconds hand for the chronograph, silvered outer seconds division for the chronograph, outer blue inner bezel with a silvered "Tachymeter" Division, date aperture at the 3 o'clock division with black calendar disk and white Arabic numerals, day aperture at the 3 o'clock position with a black calendar disk and white font for the day of the week in Englis and in Japanese (Kanji)Case: Signed, brushed stainless steel, signed stainless steel screw down crown, No.990191Strap: Generic brown leather, generic buckleSize: 38.5mm by 43.2mm The case reference 6139 is the turning point in history for the watch brand Seiko, thanks to the development of their first chronograph. Developed in 1969 and produced in small quantities exclusively for the Japanese market, these limitations turned this model into a highly sought-after timepiece praised by collectors all around the world. Another element of praise in our watch is its serial number 990191, which reveals it was one of the first 200 watches ever produced. The serial number indicates with the first number 9 that it is from 1969, the second 9 stands for the month (September 1969), and the last figures 0191stand for the watch production number 191. Dimensions Size: 38.5mm by 43.2mm.