Energizer 357/303 Batteries provide reliable, long lasting power to your important devices. Count on these button cell batteries to power your electronics, whether you need batteries for your kitchen scale, calculator or your keyless entry system. These Energizer batteries also provide dependable power for medical devices, like your glucose monitor or heart rate monitor. Each 357/303 battery holds power for up to 5 years in storage, letting you keep a ready supply of replacement batteries. Plus, these batteries contain no mercury, making them a more environmentally conscious choice.