Review on Dmyond Digital Display Voltmeter Multimeter Measuring & Layout Tools by Pete Deutsch

You can get voltage and current from these devices, but they are inaccurate compared to multimeter readings. Also, it doesn't look like they can take 30V. I fried one with 25.8V. I've used similar products from other vendors and they seem to work better. The best thing about them is their price. You can probably get readings using volts. I'm not sure about the current. I've never been able to get a non-zero current from them, but my measurements were made with circuits with a maximum current of about 12mA.