Gomadic Portable AA Battery Pack designed for the Garmin EDGE 810 - Powered by 4 X AA Batteries to provide Emergency charge. Built using TipExchange Technology Integrated circuitry regulates output voltage specific to the Garmin EDGE 810. Advanced logic maximizes overall charger efficiency. Built using the unique Gomadic TipExchange Technology that protects your investment by providing the ability to upgrade charging ports by simply swapping physical connectors. Specification: Input Voltage (4 X AA Batteries), Cable length (6 inches), Dimensions (5.0 X 1.5 X 0.75 inches), Circuit Design (Garmin EDGE 810 specific), TipExchange enabled (Yes) Safely engineered with reverse polarity protection, in the event batteries are accidentally put in incorrectly. The rugged composite design is built to last. This product is backed by our comprehensive Gomadic Lifetime Warranty.