Why settle for a standard Power Bank when you can have a super-cool oil slick one? The Mayhem Power Bank Portable Charger 2000mah Oil Slick is the perfect gadget for charging your smartphone when you don\'t have access to a power source. Charge your smartphone in style with this right on trend oil slick chargers, it\'s portable, lightweight and small enough to fit in your pocket, handbag or schoolbag. It is ideal for a quick battery boost when you need it most. It is easy to use just have the power bank charged for over 3.5 hours then away you go. The perfect device to have on hand for emergencies. . Input/Output voltage: 5 V. Battery type: rechargeable Li-ion 3.7 V. USB output. Capacity: 2000 mAh