These are 650 evod single kits. .The clearomiser is also a replaceable bottom coil, meaning the coil itself is replaceable. These can be replaced at will, without having to purchase an entire new evod style tank.
You can find the spare coils here
Spare evod tanks can be found here
To fill these- just unscrew the entire clearomiser unit from the battery, turn the unit upside down, unscrew the bottom silver ring (the coil will stay in place inside the ring), fill the tank to the top of the air channel (but not so much it will overflow into it), then screw the bottom ring and coil back on. Screw it back onto your battery and go.
To replace the coil-
Turn it upside down and unscrew the bottom ring, then unscrew the coil portion out of the bottom ring, replace, and reassemble.
*** The entire unit must be assembled properly to work right. Any gap in the seals will cause leaking and flooding issues. Take special care to be sure you assemble correctly when filling, and dont cross thread the threading. ***