In 1982 Seiko built a digital watch that changed modes by turning its bezel. It was called the Rotocall, the mechanism was a rotary switch, and Seiko notes that it found a following among astronauts. The Seiko HFL001P1 brings that idea back for the company's 145th anniversary — the bezel is still the control, and turning it still moves you through the functions.

Seiko was founded in 1881, and the anniversary collection is split into three design themes. This reference belongs to Series 3, built around Edo-murasaki — Edo purple — which Seiko uses to mark the traditions carried from ancient Edo through to modern-day Tokyo. Here it appears as a purple aluminium bezel set against a black case and bracelet, on a 37.0mm digital watch that runs a 100-hour chronograph timing to 1/100th of a second, an alarm, a timer, a second time zone and a calendar programmed to 2074.