POWERFUL BATTERY PACK: Using Grade-A Li-ion battery and premium microchips ensure reliability and 500 + recharge cycles over the life of the battery. FAST BATTERY CHARGER: Advanced technology delivers the fastest possible charge, up to 3.1 amps overall. HIGH CAPACITY & COMPATIBILITY: 10,400mAh high-capacity and dual-port charger can charge an iPhone 6 four times, a 6 Plus or Galaxy S6 two and a half times, an iPad Air once as well as many other smart devices. PORTABLE COMPACT EXTERNAL BATTERY: With the compact dimension of 5.4 x 2.3 x 0.8 inches, this battery charger is easily held in one hand (or fits into your bag) to provide instant power to smart phones and tablets. UNIQUE & SLEEK DESIGN: The harmonica-like power bank has a sleek surface treatment on its body, and brushed silver on the edge, giving you an exclusive visual and touch experience.