Gomadic Portable AA Battery Pack designed for the Garmin Nuvi 50 50LM - Powered by 4 X AA Batteries to provide Emergency charge. Built using TipExchange Technology Integrated circuitry regulates output voltage specific to the Garmin Nuvi 50 50LM. 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 Nuvi 50 50LM specific), TipExchange enabled (Yes) Safely engineered with reverse polarity protection, in the event batteries are accidentally put in incorrectly. This Gomadic Battery Pack is uniquely designed to work with both standard (e.g. alkaline) and/or rechargeable AA batteries.