Herology on X: "1975 Seiko 6139-8020 “Hexagon” 17 Jewels Chronograph around 39mm wide w/c and 12mm thick which makes this “Speed Timer” much more compact compared to the venerable “Pogue.” 👍👍👍 #Seiko #
Seiko 7016-8000 and 6139-8020] Two New Vintage Seiko Chronographs I was Lucky to Purchase! : r/Watches
6139-8020 Questions About Original Dial & Hands | The Watch Site
Tribute to the Seiko 6139-8020 Chronograph Automatic Watch | Strapcode
Seiko 6139-8020 Automatic Chronograph Full Original 1973 Model Very Rare Vintage Watch - Etsy Denmark
1972 Seiko Chronograph ref. 6139-8020 black and blue dial - TIMELINE.WATCH collection
A '71 Seiko 6139-8020 - the watch that got me into vintage Seiko. I bought the watch itself from Argentina and the NOS strap from Saudi Arabia. : r/ Seiko
Seiko 6139-8020-Speedtimer-Blue sky for AED2,182 for sale from a Private Seller on Chrono24