1,Unique design, solid structure, 2,Portable, multi-languages available 3,Working time: 135Hours 4,Standy time: 90day Folding Protective Aluminium Bluetooth Keyboard ... prices, fast delivery Specification : Bluetooth 3.0 interface standardFrequency: BT2.4-2.4835GHzReceiving sensitivity:-78dBm(Standard)RF output power: up to 4bm ...