The Lenovo Portable PowerBank is a slim, portable device which ensures your mobile device is never without power. The sleek, high quality, silver metal casing protects your smartphone battery from sudden shocks. The casing, combined with the lithium polymer cells and advanced charging technology, offer a product with enhanced safety. Perfect for providing additional power to smartphone and tablet devices on the go. *Battery life varies due to many factors, including: applications, brightness, power management, battery conditioning and customer preferences.Lenovo certified Lithium Polymer Battery Cell Intelligent charging technology for enhanced safety Ultra-portable super-slim design makes it easier to carry around High-quality full-metal shell protects battery pack from sudden shock