Gomadic Advanced Amazon Kindle (1st Generation) compatible AA Battery Pack Charge Kit &ndash; Portable power built with upgradeable TipExchange Technology Specification: Input Voltage (4 X AA Batteries), Cable length (6 inches), Dimensions (5.0 X 1.5 X 0.75 inches), Circuit Design (Amazon Kindle (1st Generation) specific), TipExchange enabled (Yes) Integrated circuitry regulates output voltage specific to the Amazon Kindle (1st Generation). 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. Internal circuit designed to protect your Amazon Kindle (1st Generation) from power surges, overcharging and short circuiting. This Gomadic Battery Pack is uniquely designed to work with both standard (e.g. alkaline) and/or rechargeable AA batteries.