Oldshark&reg; Portable Foldable Bluetooth Keyboard Ultra-slim Pocket Wireless Keyboard for iOS Android Windows PC Tablet Smartphone Built in Rechargeable Li-polymer Battery Foldable bluetooth keyboard: folding and ergonomic bluetooth keyboard, Pocket size, sleek and slim design Compatible 3 major operating system: iOS / Android / Windows. Works with most bluetooth supported devices Made of Aircraft-grade aluminum for superior rigidity, anodized matte process creates excellent sense of touch.Closed size: 5.8"*3.6"*0.7", Open Size: 9.9"*3.5"*0.2" Built-in rechargeable Li-polymer battery provides more than 60 hours of effective usage time, on a single charge. You can get Oldshark products with manufacturer warranty and customer service.