Very easy to operate. Simply connect Zoom H4n, 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 Zoom H4n (accurate to 0.1v). * Specification: Internal Battery (3400mAh lithium polymer), Input port (miniUSB), Output Port (Standard USB), Onboard Circuit Design (Zoom H4n Specific), Dimensions (4.0 X 2.0 X 0.5 inches), TipExchange enabled (Yes) * Charging kit includes: Rechargeable Lithium Battery Pack, Coiled input/output cable (expandable to 24"), Zoom H4n Charging Connection, and Battery Pack input connection. * Continue to use your Zoom H4n for hours OR recharge it on the go without being tethered to a wall outlet