Seiko 5 Actus SS automatic wristwatch, reference 6106-7490. The Seiko 5 Actus series was introduced in the late 1960s as a more progressive and sport-oriented evolution of the original Seiko 5 line. During this period, Seiko was rapidly expanding its mechanical watch technology and design language, aiming to offer reliable automatic watches that combined durability, modern aesthetics, and everyday practicality. Within the Actus lineup, models equipped with the Cal. 6106 movement occupied a particularly important position. The 6106 caliber, with 25 jewels, was developed as a robust automatic movement featuring day and date display, designed to withstand daily use while maintaining consistent performance. This movement later became the foundation for several iconic Seiko sports models of the early 1970s, highlighting its technical significance in Seiko’s history. The “SS” designation refers to stainless steel construction and a sport-focused design concept. Compared to dress-oriented Seiko models of the same era, the Actus SS emphasizes legibility and functional clarity, with applied hour markers, bold hands, and contrasting minute accents on the dial. This design reflects the shift in consumer demand during the late 1960s toward watches that could seamlessly transition between work, leisure, and active lifestyles. This reference was produced in multiple dial color variations, allowing buyers to choose according to personal preference while retaining identical specifications. As a result, the model has become popular among collectors who appreciate subtle differences in dial tone rather than overt design changes. In today’s vintage market, the Seiko 5 Actus series is valued for its balance between historical importance, mechanical reliability, and approachable pricing. While positioned below King Seiko and Grand Seiko in the original Seiko hierarchy, Actus models are increasingly recognized as honest, well-engineered watches that represent the core philosophy of Seiko’s mechanical development during its most innovative era. The stainless steel case measures approximately 38.1 mm in diameter, offering a strong vintage presence that remains highly wearable by modern standards. Fitted with a brand new leather strap. This listing is offered alongside another example of the same reference with a different dial color; specifications and construction are identical. For the blue dial version, both day and date are changed simultaneously by pressing the crown. Fine adjustment is performed by rotating the dial. The day display is bilingual (English/Japanese). Running at the time of listing. As a vintage watch, stable operation, accuracy, and water resistance are not guaranteed. The watch will be carefully packed and shipped with tracking for safe delivery.