I purchased VAAS Bluetooth Keyboard
You can buy an Apple Bluetooth Keyboard but it will cost you more.It looks exactly like Apple Bluetooth Keyboard.It requite batteries but the package does not include any.I used two Kirkland Signature AAA batteries.
Any brand will work fine.Close the battery cover and turn it on.There is a small black button black says "Connect".On iPad side, go to setup and go to bluetooth. Make sure it is On.It detects the keyboard and ask you to type 4 numbers.
Type those 4 numbers and hit "Return".
It is that simple.Now your new keyboard is connected to your iPad.It is like having a small computer. I like it.
It was very easy and it should increase your productivity using iPad.