TeckNet Power Bank 10000mAh Waterproof Dustproof Shockproof Portable Charger USB External Battery Pack with Compass Carabiner for Mobile Phones and Tablets 88% charging efficiency, 5-10% above other 10000mAh external batteries. 10000mAH Capacity add more than 3 full charge or 30 hours of additional talk time to your iPhone All-Weather Power Bank: Waterproof, dustproof, and shockproof; tough body with Ingress Protection Rating of IP67. Multi-functional: Built-in torch and handy compass included, perfect for camping and hiking. Impressive Performance: Max 2.1A output can charge almost any smart device at top speed; DC 5V 2.0A input, saving up to 50% of the charging time. Package contents: TeckNet iEP900 10000mAh External Battery, 1x Compass, 1x Carabiner, 1x Strap, 1x Micro USB Charging Cable , 18-month warranty and friendly customer service.