The Tekpower HY3006D is a single-output DC variable power supply with a voltage output from 0-30 volts and a current output from 0-6 amps. This highly stable, high quality DC power supply with its output continuously adjustable at 0-30V DC and 0-6A. What's more, the unit is equipped with coarse and fine controls for adjusting both voltage and current, making it extremely easy to set the output to your desired level. The unit comes with 2 back-lit LCD displays, providing accurate readout for the voltage and current values. It comes with a input selection switch, you may use with 110V or 220V. It is used in a school lab or science central. The ripple is small and voltage is stable.