The Dell™ black power companion external battery pack with 18000 mAh capacity, offers reliable backup power. It is suitable for use with Ultrabooks, Notebooks, tablets and Smartphones. This battery pack is compatible with Inspiron 3551, Inspiron 11 3000 series, Inspiron 13 7347, Inspiron 13 7000 series and more. It has two 4-pin USB type A power output connectors to connect external devices. The lithium ion battery technology provides efficient performance. This compact power solution comes with two charging cables to charge simultaneously a pair of mobile devices.