It has a built-in rechargeable battery (battery life of 3 months) usb cable to plug into a USB port on your computer or on a charger (not site leisure).
Once side switch ON, I connected to my Bluetooth tablet easily.
I was surprised by the quality of workmanship, firm and elegant this case / keyboard has a very ergonomic and allows pleasant typing text. it contains the specific shortcut keys to Android handy in this case.
This is a great product but is aimed at a professional audience both in its conception and its price of over 120.