I have Power banks just like the one in the pic in Black, White, Green, Yellow, Blue and Pink. It is good for one charge of the phone and then plug it in again and have it ready when you need it.
They can be charged again and again for use with any phone when you are low on battery and need some extra juice. I have been using the same one for over a year and it still charges my phone.
Let me know the colour you want and I will see if I have any left.
Thanks,