Gomadic Portable AA Battery Pack designed for the Voice Caddie VC300 - Powered by 4 X AA Batteries to provide Emergency charge. Built using TipExchange Technology Integrated circuitry regulates output voltage specific to the Voice Caddie VC300. 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 (Voice Caddie VC300 specific), TipExchange enabled (Yes) Internal circuit designed to protect your Voice Caddie VC300 from power surges, overcharging and short circuiting. This Gomadic Battery Pack can be reused forever by simply inserting fresh batteries, providing instant power on demand.