Discover Swatch's precision with the Sistem 51 (ref. SUTF400), a contemporary classic shaped by careful watchmaking know-how. The exterior is thoughtfully executed: crafted in plastic and measuring 42 mm in diameter, with a thickness of 13.8 mm, defined by a round silhouette. The caseback is open, and the crystal is plexi, delivering water resistance to 3000 meters. At a glance, the dial balances texture and clarity: a black tone with sunburst finish, framed by arabic numerals hour markers, and stick hands. At its heart beats a proven engine: the Sistem51 caliber. Introduced in 2016. With considered ergonomics, it feels composed during extended wear. Brushed and polished elements play with light to emphasize crisp geometry. For buyers researching specifications and real-world impressions, this reference stands out for coherent design, dependable mechanics, and lasting relevance within modern horology.