From the master craftsmen at Seiko, the Seiko Men's SNKK71 Seiko 5 Automatic Black Dial Stainless Steel Bracelet Watch is an innovative watch with a masculine appeal. Including a black analog dial and a silver stainless steel band, this watch is packed with design and would be an excellent addition to your watch collection.This is an automatic mechanical watch. Automatic watches do not operate on batteries; rather, they are powered automatically by the movement of the wearer's arm. If the main spring in your automatic watch is not wound adequately, timekeeping might become less precise. In order to preserve accuracy, wear the watch for 8 hours or more per day, or by hand wind the main spring by turning the crown. When not in usage, automatic watches might be kept accuseded of an automatic watch winder-- a watch storage device which might be purchased individually.