Review on Enhance Testing Accuracy with Power Probe 5-Volt Reference Adapter by David Merculief

I got this for my son who works as a mechanic and I got him a Power Probe for Christmas a few years ago and mention that PP is the killer called "ECU[M]" since you can accidentally apply 12VDC when testing related circuits. This 5V DC shunt, when used properly, will not allow you to apply more than 5V DC to the circuit under test. My son was delighted to get this as a stocking filler this year, he said it would save him a lot of work and time.