In 1969 Seiko introduced the world’s first automatic chronograph, the Seiko 6139, often called the “Speed-Timer”. Production of the Seiko 6139 line up ended sometime in 1978, but are still readily available today. The 6139-600X series is quickly becoming very collectable pieces thanks to a combination of great design and storied history. The 600X has two big claims to fame, as both a contender for the world’s first automatic chronograph and as the first chronograph worn in space.
CREDIT: SeikoUSA.com