"Power Tube Simple 2600 is an all-in-one external battery with built-in 2600mAh battery specially designed for Micro USB powered devices, available in 5 vivid plastic colors. The special feature of this Power Tube is a push-up connector tip which has male Micro USB on one end and male USB on the next. The micro USB connector can be used to charge Android, Blackberry and Windows phones, or most Micro USB powered devices. The male USB connector is designed to re-charge the Power Tube SIMPLE via any powered USB equipment. No extra cables are needed for charging and re-charging, easy to use. Re-charging status indicators (red and blue) are designed to tell the charging status when it's connected to a powered USB equipment, red means charging and blue means fully charged. And a yellow LED indicator is in place when the battery level is below 15%.Popular Compatible Models (Built-in Micro USB connector):Samsung: Galaxy S5 S4 S3 S2 / Galaxy Note 3 2 / Galaxy Nexus / Focus S / Infuse HTC: One (M8), One, One max, One mini / Desire series / Butterfly series Motorola: Moto X / Moto G / Droid : Nexus 5, 4, G2, Optimus 4X, 2X, V, S, T, 3D, 7Nokia: Lumia 1020 920 900 710 800 / N8 / N9Others: Most of Android Phones / Google Glass / Blackberry / Sony Xperia Z1 / PSP / MP3 MP4 MP5 / GoPro".