Good description on what it is. Fail Zero is the leader in NiB in AR's. It isnt always going to be shiny if used in a BCG, and it will wear. The best part is it is super smooth specially when rubbing up against more NiB. I'm not a fan of 2 tone guns so I passed on NiB on my slides. But I will, if at all possible keep NiB on my AR BCG's and LPK's. I have a Spikes M4 with the full NiB and a Spikes Middy with the standard phosphate. The standard stuff though smooth and 100% reliable with litle lube feels and sounds like sandpaper compared to the NiB dry. Is it necessary in an AR-no, is it better-YES. Heck, I will even have some of my bullpups important parts NiB'd when the next ATEi NiB opportunity comes. It works for black rifles and I'm sure if applied to the proper areas it will make a good pistol a great pistol.