... is for waterproof ,dustproof, shock absorption Specifications 1, executive standard: Bluetooth V2.0 2 Working distance: 10 meters 3, modulation system ... -20 - +55 °C 20, Storage temperature: -40 - +70 °CNote: When you switch on the keyboard, the power light and Bluetooth light will ... use ,the power light will keep lighting ,but the bluetooth light will be off after it successfully connect to device ...