Pulsar P-1.
The P-1 LED watch was developed and produced by Hamilton using the Pulsar name. "First ever sold solid-state watch". This beauty would of cost you $2100 in early 1972. Roughly 400 units where produced in 18k Gold, with synthetic ruby time-screen.
Probably one of the most important watches in modern time.
Probably one of the most important watches in modern time.