Okay, long story short I bought this in the belief that this was in FDE. Word to the wise, never buy something that was pictured in yellow light. I was tinkering around with it and found it to free float most of my upper/barrel combos, but without the anti-rotation tabs I wouldn't recommend putting it on a defense rifle. This would be perfect for say a .22 build or a 9mm, but if you have the skills who knows what you can do with it. I have all the pins that you need in order to mount it on a Ruger SR556, but unless you need a spare, it probably wouldn't serve you any good. The rail is in very good condition, no significant nicks or dents.
Top rail @ 9 1/4"
Side and bottom rails @ a little under 11"
Uses a modified barrel nut, and held in place with a steel roll pin
The barrel nut does show some wear, but is only cosmetic, nothing to disrupt it's mounting or operation. This could be a a nice part to free float your rifle. For 130 shipped (+4% for paypal), you can have a free float for the cost of a drop in.