Ten-year batteries are invariably Lithium-type. They are quite thin but have a much larger diameter than silver oxide types so the two are not interchangeable. The watches are designed to take one type or the other as the voltages are also different. If, like me, you dislike the hassle and expense of frequent battery changes, I can also recommend light-powered watches (such as Citizen's Eco-drive range) - they can be quite inexpensive, are terrific quality and go on forever.