A brief green LED for Power after the keyboard is opened means the keyboard has sufficient charge for operation and is ready to use.A red LED for Power indicates the keyboard is charging.A blue LED for State means the keyboard is broadcasting its existence through Bluetooth, and can be discovered by your tablet or phone.A green LED for State means the keyboard is operating in USB mode (BT-KEY3XL only).You can switch back to Bluetooth mode by pressing Fn + 1.A red LED for Caps indicates Caps Lock is on.