These are size cr2 3.0v non-rechargeable lithium batteries. They are NOT the same as cr123a batteries and are not interchangeable with CR123A batteries. It is not recommended to mix old and new batteries for usage. These batteries are not compatible with for Arlo cameras. 3V Lithium photo battery that can be used in many high energy applications such as golf range finders, photo cameras, flashlights, light meters, toys, clocks, and other photo equipment. Tenergy's cr2 lithium battery has 800mAh energy capacity. High energy drain devices like digital cameras work longer and record more. Tenergy's lithium cr2 3 volt battery has a short and consistent cycle time, ideal power for high drain devices that require bursts of energy. Lasts for 10 years on the shelf with very little discharge. Store the battery in a cool and dry environment, avoid direct sunlight, and keep away from intense heat like fires or liquids. Tenergy Propel CR2 Lithium non-rechargeable lithium battery delivers long run times in every device that it powers whether it is an LED or incandescent flashlight, a camera, or a high tech gadget. Independent tests have shown Tenergy Propel CR2 batteries excel in higher drain devices and often outperform the big names; cells in those types of devices. CR2 batteries can power many flashlights Consistently rated as a consumers top pick for CR2.