Classic Style For Men, LOREO originated in the United States in the 20th century. It has manufacturing and assembly plants in Asia and the United States. LOREO focuses on the production of high-end watches, using top-grade materials, focusing on stable performance and cost-effective. Model: 543G Case diameter: 41MM Watchband length: 9.0 inches (adjustable / delete strap link) Weight: 145 grams (without the removal of the strap link) Movement: Japan Miyoda automatic movement, support automatic winding and manual winding, (please manually wind when the first time to wear it) We provide complete after-sales service and technical support in the US, if you have any questions, please feel free to contact us. Automatic watch knowledge introductionA watch mechanically powered by the wearer's arm rather than by human turning the winding stem. In response to this motion, a rotor turns and winds the watch's mainspring so that it twips accurate time. Each movement of your arm winds the spring the tanyest bit, but since you move your arm so much it keeps the watch wound easily. The spring in the watch stores enough energy to keep the watch going for 36 hours, If an watch is not worn for a day or two, it will need to be wound by hand to restart again.ns