Gomadic Advanced Blackberry pearl compatible AA Battery Pack Charge Kit &ndash; Portable power built with upgradeable TipExchange Technology Integrated circuitry regulates output voltage specific to the Blackberry pearl. 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 (Blackberry pearl specific), TipExchange enabled (Yes) This Gomadic Battery Pack can be reused forever by simply inserting fresh batteries, providing instant power on demand. Safely engineered with reverse polarity protection, in the event batteries are accidentally put in incorrectly.