Elbit Systems of America External Battery Pack For AN/PVS-31D- 3 Cell Black NSN 6130-01-686-5278. This accessory significantly increases the battery life of the device powering the goggle for hours longer than possible with the single battery typically used to run the device. Tested to be water resistant at 20 m (66ft) for 2 hours. Specifications for Elbit Systems of America External Battery Pack For AN/PVS-31D- 3 Cell: Manufacturer: Elbit Systems of America Color: Black Length: 3 Width: 1.5 in Height: 3.125 in Weight: 150 g Features of Elbit Systems of America External Battery Pack For AN/PVS-31D- 3 Cell Supplies power to the AN/PVS-31D night vision goggle Significantly increases battery life of the night vision device Water resistant at 20m (66ft) for 2 hrs Package Contents: Elbit Systems of America External Battery Pack For AN/PVS-31D- 3 Cell Elbit Systems of America 286234-1: External Battery Pack For AN/PVS-31D- 3 Cell Black NSN 6130-01-686-5278