Awesome quality - the best silver oxide batteries in the world. Made by SII Micro Parts, Ltd. SII is one of the largest micro battery producers in the world. Most cellphones in the world have SII batteries for memory backup. Their silver oxide batteries are used exclusively by Seiko watches, but desirable in any watch. 25 models to choose from. Buy directly from the importer/master distributor. AT THIS MOMENT ONLY MODELS 364 and 377 IN MERCURY FREE ARE AVAILABLE..