Chronoswiss Watch Sirius Opus Chronograph Skeleton CH-7543.1S-SI. The original Chronoswiss Opus launched in 1995 marked a significant cornerstone in the luxury watch brand’s development of skeletonization. Today, the Chronoswiss Sirius Opus Chronograph Limited Edition represents this history and their ground-breaking technical prowess with traditional accents married to contemporary improvements. The design has been thoroughly updated for modern-day wrists with sleek geometry, a 41 millimetre case size, shorter lugs and as expected, a complex skeletonised dial. The openwork centre is engineered from solid sterling silver and achieved by trimming away any superfluous metal to reveal the Caliber C. 741 S automatic winding movement within. The Swiss made calibre is just as much accessible through the dial as it is through the case back with a sheet of sapphire crystal revealing some of the 25 jewels,  polished escape wheel and screws, perlage decorated bridges and plates and the skeletonised and rhodium plated rotor classically striped with Cotes de Geneve decoration. Thanks to the movement, the Chronoswiss Sirius Opus Chronograph watch also benefits from a power reserve of 46 hours and displays for hours, minutes, small seconds, central chronograph seconds, 30 minute counter, 12 hour counter and analog date. Each of these functions are signalled by lacquered and curved hands in silver and orange. The case of the Chronoswiss Opus Chronograph is crafted from polished stainless steel and completed by domed anti-reflective sapphire crystal glass, a polished screw down bezel, a water resistant rating of 100 metres and a sophisticated black Louisiana alligator leather strap.