One 4-pack of lithium CR2 3-volt battery with 800mAh capacity - these batteries are different than CR123A and NOT interchangeable Ideal for digital cameras, flashlights, night-vision goggles, calculators, memory backup, and more Reliable in both high and low temperature environments Ships in Certified Frustration-Free Packaging Note: these batteries are NOT rechargeable. For reusable options, check out Amazon Basics rechargeable batteries Dimension: Diameter: 0.6 inches; Height: 1.05 inches