Review (5/5): quality product.
This is a great power supply that can feed up to two tattoo machines, the voltage is regulated through the knob and you need to twist it to the left and right in order to increase or decrease the speed, it can provide from 1.5 to 12v of power.
It included the power supply and the wall adapter so make sure you have your tattoo gun cables to have everything ready.
The supply is sturdy and has rubber on the bottom so it doesn't slip while used. The only downside I could find is that the knob is a little hard and ups and downs really slow the voltage, so you need to twist it a lot in order to go from 1 to 12 volts. Other than that is a great supply.