This particular timepiece, produced by the Daini division, offers a sleeker and more slender design compared to the 6139 model from Suwa. It was developed as a response to the 6139 series, providing a compact form factor. Notably, it incorporates a "flyback" function, allowing the chronograph sweep to be reset without stopping the mechanism.
 
This specific example, manufactured in September of '71, is in pristine condition, appearing as if it were made to meet today's standards. The dial has a striking matte black appearance, complemented by an orange minute track and the "Speed Timer" label. Additionally, it features a rotating inner bezel adorned with silver and steel gray markers.
 
The hour and minute hands are polished and beveled batons, matching the applied markers, while the vibrant orange sweep hand adds to its allure. Being a JDM (Japanese Domestic Market) variant, the day of the week display can be switched between English and Kanji characters. It is positioned alongside the date, enclosed within a polished frame. The tonneau-shaped case boasts ergonomic contours and flared sides, making it one of the most comfortable designs in the Speedtimer series, suitable for daily wear.