Joyetech BF RBA Head for CUBIS and AIO
These will work with the Cubis and the AIO. Comes prebuilt with a .5 ohm coil.
This product comes with
Can be built vertical and horizontal:
I these RBA heads. I personally picked up 5. I only use them with a vertical build, and while it took a few tries, it really wasn't that hard to get used to rebuilding. It is a little larger than the standard heads, so you lose a little capacity.