There are regular specialty batteries and then there are Energizer specialty batteries. So get the durable, reliable power that keeps going with this Energizer 357/303 silver oxide button cell battery. It delivers long-lasting power to your button-battery-operated devices, from household electronics like keyless entry systems, to e-books, toys, calculators and watches, to heart rate and glucose monitors. Choose Energizer specialty batteries for long-lasting power you can count on when you need it.