I love these 801 Fusions so much! I just bought about the last 25 from Ikenvape lol. The stainless steel ones are so badass. Greatest cartomizer. @ 3.7 its a nice cool flavorful vape, and @ 5 volts its just incredible vapor and flavor! Less vapor than a dual coil maybe, but better in every other way IMO, less battery drain, better flavor, burns less
juice, etc.
With the battery SP2 comes with the Fusions should screws down about all the way. With the ultrafire batt I have, I can screw both caps onto the SP2 fully, but then the Fusion screws on only about one twist or so, but its pretty firm on there. Or screw the Fusion down all the way and just leave the bottom cap not screwed on all the way.
With my Megladon batt in my Thermo, I slap 2 rare earth magnets on the positive end, screw the Fusion down all the way and its a perfect snug fit - and looks sexy with the stainless steel fusions with silver whistle tip. These cartos can pump massive vapor at 5volts and retain their flavor nicely and for pretty long. I'm only going to use these cartos from now on most likely. At 3.7 I really get a good taste with them, and the aluminum whistle tips aren't bad either.