Actually, what I wanted to know is the difference between a "Commando" and a regular Sig 556. I have read threads that it is just "a few green parts". I have 3 of these guns and each are a little different. I like Sigs and if this one has something specifically and notably unique I would be interested in buying it. I looked on Sig"s website and other sites and can find no specific differences. I have contemplated taking one of mine apart and having it coated/painted.