LOBINNI Automatic Watches For Men Luxury Fashion Stylish. The self-winding system is a system that gets power by mounting it on the arm and automatically winding the internal spring with the force of the arm shaking. Artificial Sapphire Crystal Featuring a 42mm case, 21mm band width, scratch-resistant mineral crystal glass, Automatic machinery analog display, imported. The watches' mirror is made of 1.2 mm artificial sapphire and is extremely resistant to abrasion and scratching. The artificial sapphire material is second only to diamond in hardness which can withstand for lifetime using and remains flawless. 316L Stainless Steel Case Forged from 316L stainless steel which has excellent gloss and hardness and strong corrosion resistance. The hardness is much higher than normal stainless steel watches. High-quality materials and craftsmanship to ensure lifetime durability and excellent strength. 30mm Transparent caseback AAAA-level fully automatic mechanical movement, frequency 21,600 times/hour, moisturizing number 19, power reserve of more than 40 hours, At the core of LOBINNI is an innovative belief that you deserve the best so that you look and feel unstoppable.