iStick 30w instead of the 20w. The 20w was the first iStick model and has some problems that have been corrected in the 30w. The problems are that it runs hot at lower volts/watts. It actually puts out 4.1 volts when the screen shows 3.1 volts. This levels out as the voltage increases. The 510 threads are chrome plated brass, not stainless steel. They are easy to mess up. The 510 pin is not spring loaded. It can get depressed resulting in the need to get an object under the pin to lift it. Go for the iStick 30w with an Aspire Nautilus Mini or Eleaf GS Air, M, MS or GS Tank. They are dependable devices.
Phil Busardo review: