This timepiece, manufactured by the Daini division, serves as a sleek and slender alternative to the 6139 series produced by Suwa. It offers a more compact design and includes a "flyback" function, allowing for the reset of the chronograph sweep without needing to first stop the mechanism.
The particular example we have from April 1971 is in pristine condition, appearing as if it were manufactured by today's standards.
 
The dial showcases a refreshing matte navy hue complemented by an orange minute track and the distinct "Speed Timer" designation. Additionally, it features a rotating inner bezel adorned with silver and steel gray markers.
 
The hour and minute hands take the form of polished beveled batons, harmonizing with the applied markers, while the vibrant orange chronograph sweep adds an appealing touch. Being a Japanese domestic market variant, this timepiece allows for toggling the day display between English and Kanji characters. The day and date are presented beneath a polished frame. The tonneau-shaped case exhibits elegant contours, and its flared sides contribute to the exceptional comfort of this model, making it suitable for everyday wear.