Wow, is this not the most useful thing you did not know existed or what? It's a switching wall adapter where you can easily change the voltage! It's like a benchtop supply you can take with you anywhere.This model is 10 Watts and has 6 selectable outputs ranging from 3V to 12VDC and up to 1.5A output. It has a 2-prong plug but takes 110VAC to 240VAC so you can use it anywhere with a simple plug adapter.It comes with a range of tips, such as 2.5mm mono, 3.5mm mono, 5.5mm/2.5mm, 2.5mm/2.1mm, 4mm, etc. You can also change it from center positive (most common)...