K plug polarity

Hey guys,
I just have a quick question on the polaritys on this plug. Which on is positive and which one is negative.
-Sorry for the bad image quality
-The front is a negative sign

it is really easy to check if you have a voltmeter or led and a battery

Yep i’ve got a voltmeter

Now you just need to know what pin is for outside part of the barrel using continuity check with voltmeter.
As for the polarity it depends on what are you planning to plug it into. Usually outside part is negative.

I have a couple of these from Radio Shack, and I gotta say they couldn’t have made the labeling any more confusing. The positive/negative indicator is offset exactly 90 degrees from the pins, so there is no way to tell which is which without a quick voltmeter check.

@ noob123 - once you figure it out, grab a sharpie and mark that thing up!