5 series
The Seiko 5 series is a line of affordable, automatic watches produced by the Japanese watchmaker Seiko. The line has been running since 1963 and is one of Seiko's most popular models. The 102-HEAD part of the Seiko 5 series is a line of self-winding mechanical watch movements that came on the market in 1976. This movement has a day-date display, 25-jewel mechanism, and is capable of a power reserve of 50-55 hours. It is considered the workhorse of the Seiko 5 series, as it powers many of the models available. In addition, it launched the “Magic Lever” system, which makes winding a breeze even in low power reserve situations. The 102-HEAD is highly respected for its durability, value, and accuracy and is still in use today.