INNOVA Equus 3420 Smart 12V Test Light / Logic Probe
It's really just a test light that automatically senses POS or GROUND, however it is some times refered to as a logic probe.
Equus 3420 http://amzn.to/2kBAofP
I actually used this to build a homemade power probe. Worked pretty well, but ended getting another one of these little guys because i liked it so much.
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