WKB-1700M Connects to Smart Phones and Tablets via BT 3.0.It has Quick Switch between BT1, BT2, BT3, BT4:Fn1-4.The Bluetooth Keyboard for Mac supports Sleep and Wake-up function. It Built-in Caps Lock/Pairing/Battery Low LED indicator function and On/Off switch maximizes battery life function. The power supply is 2 AAA batteries.