Arduino DC Barrel Connector Length?

Hello, all!

I've searched and search, and can't find the information I seek...

What is the length of the connector that is recommended for use with the Arduino? Tayda Electronics has two connectors that are both 2.1mm, but they are different lengths:

I'm sure the longer one would still work with it, even if it isn't the correct one, but would prefer it to be the right size.

Thanks!
ElectroPulse

I measure it to be 10mm deep.

Weedpharma

Ok, so sounds like the 14mm would be required in order to insert fully... Thanks!