KS Aviator Automatic Mechanical Date Men's Sport Military Wrist Watch Designed by renowned German Watch Maker "Mr. Ludwig van der Waals". He won numerous awards in many recognized creative design competitions around the world. Precision Movement with the latest breakthrough "Kronen & Sohne" Patented Mechanical Technology. Specially designed with Stainless Steel Case and High Quality Leather Watch Band. Water resistant up to 3 ATM (Not suitable for swimming, diving, shower etc.) Please note this is a MECHANICAL WATCH which will stop working if you are not moving for a long time. Please wind up the watch before EVERY USAGE, and keep the watch away from magnets to ensure the watch keeps working. For detail instructions of the watch, you can access our Kronen & Shne official website to download. If any questions, dont hesitate to contact us.