If you're wanting a PT that can be run from your computer safely, you need one that has an inline battery (they are 3.7V). If you want a 5V (no inline battery), majority of vendors carry them. These are 5V PT's and are not safe to run on a USB connection. Computers don't supply the proper power to fire these which can lead to your computer being damaged. Use a wall charger for all 5V PT's. There isn't a PT that's better than another IMO. Majority of them are made by the same manufacturer in China. The only ones I would say are better are from madvapes.com...5V...handmade...but cost $30. Piper makes a 3 stage (3.2, 3.7, 4.2V) passthrough but I don't care for them. Gotvapes and a few other vendors sell these. Ego also sells a battery that can be charged and vaped at the same time...another 3.7V.