well just got mine in today, and i've been using it in the place of my 5v pass on a battery pack. The 4.2 hits almost as hard as the 5v (the 5v probably meters in at 4.4v or so) I like the smaller size which fits my Vision's perfectly. The 5v is an 808 style pass so in addition to being longer I have an adapter on it as well. I wish my ego batteries could be this short while still having the capacity of a 900mah. My only complaint and it's a tiny one, is that my battery pack goes into standby and when I reactivate it I will have to reset the pass to whatever I was vaping. Not an issue most times but for my specific use it is a little annoying. Also I would have liked to see no cut off, or rather a 20 second one instead of a 10sec. It isn't the manufacturers fault for not making it for my unique usage. I bought it to be in my center console, and it fits the bill with flying colors. It may end up replacing my other pass for on the go passthroughing. In any case it is exactly what I paid a great price for. I like that it comes with a case too.
