I wanted to pop in here and say that the ego variable voltage pass-through actually only goes as high as your laptop/computer will allow it to go. I have heard a lot of weird things about the ego PV. How much are you looking to spend on a vv device? Are you on a tight budget, or do you want something that will last forever? Because cutting corners has its advantages, but a GOOD mod has its own advantages. Why are you looking for vv? Is it the throat hit? If it is the throat hit, then you will get good throat hit at 3.7 volts on just about any 18650PV, with low res atty/cartomizers. The Riva batteries have a good following here on ecf and they are easy to recommend, but there are just SO MANY mods and PVs. 3.7v with low res is a great starting point and you may never need a vv device. However if your the type that will want to see what vv has to offer, or if when you were a smoker, you basically needed a cigarette in your mouth at all times, like i did, or if you NEED good flavor and throat hit, then going strait to the vv device is a good idea. With vv price is the problem. The VV Saber mods actually have a built in pass through battery if you order it, which is one of the coolest pv features i've ever seen. But with this, your going to pay over $100 for the mod. The K-GO aka RIVA OR Genuine JOYE 3.7 volt batts are great as well, or the Roughstack, the Silverbullet, the Omega, the boxmods out there, they are all great 3.7v mods to pair with low res equipment for the vape that most people enjoy. Riva: $45.00 MODS: $100-150 Riva: 8 hours life 18650 MODS: 1.5 day(s) battery life. So, the mods have better battery life and replaceable batteries. Right now there are some websites with great deals on the Lavatube/L-Rider/Vtube variable voltage mods. You can get one for under $80.00 at the moment. ApolloEcigs is where I just ordered mine and you get a kit for the same price as a Riva kit. If you need a small size, Riva is the way to go. I'm just finding out that Kalamazoovaporshop.com has some cool VV models and they also carry 18650 Ego-T batteries. I'm definitely still learning myself. Cool stuff.