Portable Emergency AA Battery Charger Extender suitable for the Sirius StarMate ST2 - with Gomadic Brand TipExchange Technology Integrated circuitry regulates output voltage specific to the Sirius StarMate ST2. Advanced logic maximizes overall charger efficiency. Specification: Input Voltage (4 X AA Batteries), Cable length (6 inches), Dimensions (5.0 X 1.5 X 0.75 inches), Circuit Design (Sirius StarMate ST2 specific), TipExchange enabled (Yes) Built using the unique Gomadic TipExchange Technology that protects your investment by providing the ability to upgrade charging ports by simply swapping physical connectors. The rugged composite design is built to last. This product is backed by our comprehensive Gomadic Lifetime Warranty. Easy to operate. Simply insert batteries, toggle on/off switch and your Sirius StarMate ST2 will start to charge.