Unique Gomadic Portable Rechargeable Battery Pack designed for the Garmin Nuvi 750 - High Capacity Gomadic charger that fits in your pocket Specification: Internal Battery (7800mAh lithium polymer), Input port (microUSB), Output Port (Standard USB), Onboard Circuit Design (Garmin Nuvi 750 Specific), Dimensions (2.75 X 3.25 X 0.75 inches), TipExchange enabled (Yes) Very easy to operate. Simply connect Garmin Nuvi 750, press activation button on pack, and charging begins. Quick start guide included. Integrated circuitry tailors output voltage and charging current to exact specification of the Garmin Nuvi 750 (accurate to 0.1v). Built using unique Gomadic TipExchange Technology that protects your investment by providing the ability to upgrade charging ports by simply swapping the physical connector. Continue to use your Garmin Nuvi 750 for hours OR recharge it on the go without being tethered to a wall outlet