History of the Seiko 5 Actus SS The Seiko 5 Actus line was introduced in Japan in the late 1960s, positioned as a youthful yet reliable extension of the legendary Seiko 5 series. The “Actus” name was derived from the Latin word meaning “active” representing a new generation of automatic watches designed for young professionals who wanted style, performance, and everyday durability. The “SS” designation on the dial stands for Seiko Sports, emphasizing robustness and improved water resistance compared to standard dress models. The Seiko 5 Actus watches were part of Seiko’s effort to appeal to the growing domestic market, particularly among university students and young office workers in 1970s Japan. Produced by the Suwa Seikosha factory (indicated by the Suwa logo above 6 o’clock), this model ,reference 6106-8420 , houses the reliable Caliber 6106 automatic movement working fine not serviced known for its 23 jewels, day-date function, and hacking seconds feature. The tonneau-shaped case and minimalist silver sunburst dial reflect the bold yet refined design trends of early 1970s Japanese horology. Description Brand: Seiko Model: Seiko 5 Actus SS (Sports) Reference: 6106-8420 Movement: Automatic, Seiko Cal. 6106 (23 Jewels, hacking seconds, quickset day/date) not serviced Production Era: Circa 1970 Manufacture: Suwa Seikosha, Japan Dial: Silver sunburst finish with applied bar indices and baton hands Case: Stainless steel tonneau case, brushed and polished surfaces Crystal: Acrylic (domed) Water Resistance: “Water Resistant” (original factory rating) Strap: Black leather (aftermarket replacement) Case Back: Screw-down stainless steel with Seiko 5 Actus engraving Functions: Hours, minutes, seconds, day-date (English/Japanese display) Timestamp: https://imgur.com/a/YhbtQWM Price 275$