Identify ULT

[BlackOps]

I'm sure this has been asked a dozen times. I tried to search for it, but I'm apparently not hitting the right combo of words.

I recently bought 2 x-valved mags and wanted to know what was the quickest and easiest way to identify if they have ULT's installed in them?

[reckid1986]

RT on left, ULT on right
if you leave the on/off in the valve the rt will have a small pin about 1/16"
the ult will have about a 1/8" pin with a small hole in the center.

[BlackOps]

Thanks!