IWC Portofino series, model: IW510103 Case: Made of stainless steel, 45mm in diameter, 11.7mm in thickness, 30-meter water-resistant for daily use, double-sided anti-reflective raised sapphire crystal, transparent case back • Strap: Dark brown Santoni alligator leather strap (22mm wide), with a stainless steel pin buckle • Movement: Self-produced Cal.59210 manual winding movement, 30 jewels, 28,800 vibrations per hour, 192 hours (8 days) power reserve, Geneva stripes finish, supports stop-seconds function. Eight-day long power reserve: 192 hours of power reserve, no need to wind the chain frequently during daily wear, more worry-free in business trip and travel scenarios Multi-display layout: Calendar window at 3 o 'clock, power reserve display at 9 o 'clock, and small seconds dial at 6 o 'clock. The functions are practical and the dial surface is balanced and harmonious Self-manufactured movement craftsmanship: The Cal.59210 movement is made by IWC itself, with fine finishing. The transparent back allows for a direct view of the movement's operation. It is a representative work of the brand's long-term power technology