I recently received the new v2 cthulhu tube mod. It is both similar to and different from the v1. Both are mosfet, usable in either 18650 or 18350 mod. They are both 24 mm and the v2 is slightly taller than the v1. The biggest, and to me, best difference between them is that the v2 has a lovely lovely bottom fire button, which is very similar to that on old school mechs. The v2 also has a battery indicator light, which is handy. Both mods work well but the bottom switch on the v2 is enough reason to get it over the v1. This is a very reasonably priced, nice looking, and fully functional 'semi-mech' mod, that fires down to at least .3 ohms in 18650 mode. In my book, it's a winner! Thanks for reading. 
