It may not have threading. Looks a lot like the iTaste - which connects magnetically instead of threads. Description from Kanger below:
Size 132*13.8mm
Cartomizer resistance 2.1-2.4ohm
Cartomizer capacity 2.0ml
Cartomizer color available blue, grey, clear
Battery capacity 650mA
Battery color available black, white
1 set includes * 2 batteries
* 2
tank cartomizers
* 5 coil unit
* 1 wall adapter & USB cord
* 1 user manual
* 1 gift box
Edit: Just to complicate things a little, there's the Kanger S1 and the Kangertech S1 which is advertised as having "unique threads". Whether or not that means magnetic I dunno.
Edit: (lol) - not magnetic apparently.