In 1978, Tissot created a quartz model that featured a slim case, slim indexes, and a steel bracelet. Its wide, horizontal lugs, typical of the time, were perfectly integrated into the flat, tonneau-shaped case.
A few years later, Tissot registered the name PRX. “PR” stands for “precise” and “robust”. The “X” stands for the Roman number ten and for the pressure of 10 bar, which corresponds to a depth of 100 meters, to which the watch remains water-resistant.