This Energizer CR1620 Lithium Battery offers you power that you can depend on. It has a quality blend of materials that makes it shelf stable for up to 8 years, so you can keep back ups on hand for quick changes when needed. The 3V lithium coin battery has the plus sign clearly labelled on top so you can replace it quickly and effectively. It's designed to fit into a variety of electronics from keyless entry points to heart rate monitors. This battery is a replacement option for a variety of sizes.