Kr8 and Greencig have the same threading on the battery so they can both be used on a Kr8 battery as long as it has a slot cut across the positive terminal of the connection. All of my autos have that slot. Some of my manuals don't. You might need to use an adapter or staple mod to let in air.
Most think the Greencig cartomizers perform better, but the Greencig cartomizers ARE a lot more complicated to refill than the Kr8 cartomizers. And V4L Premium means the liquid is 'better' and there is theoretically a difference in the design. They don't seem premium to me but that is just my opinion.
If you have your own liquid that you like I would recommend that you get a Kr8 kit with empty cartomizers. You can use the
Condom Refill Method with your liquid. I do it from the mouthpiece end though.
If you want short batteries
V4L has a good selection. If you don't mind the standard length batteries I would recommend
LiteCigUSA.
Good luck!
