Duracell - DURDL303357CT Silver Oxide Button Battery delivers long-lasting, dependable power. With Duralock Power Preserve Technology, it stays powered for three years in storage. The Duralock guarantee gives you the comfort of knowing that the Duracell batteries sitting in your drawer will still work when they are needed most. Best uses for this 1.5-volt battery include medical devices, watches, toys and calculators. Battery is equivalent to SR44, SR44W, EPX76, SR44SW, 303, 357, D303/357, V303, V357 and SR1154. It contains no mercury.