TECH SPECS:Li-Ion Internal PDA Battery 2000 mAh Ultra High Capacity Voltage : 3.7vPart no. X1111DELL Pocket PC PDA MODELS: DELL AXIM X3 DELL AXIM X3iDELL AXIM X30This extended capacity battery is a twice capacity equivalent of your standard battery.It comes with a special battery cover for your PDA as the battery is twice thicker than the standard cover allows. Only such battery construction allows double extended capacity