I have a Rock River Carbine Mid A4.It is a model 1207 yankee hill quad rail,low profile gas block,Hogue grip.Bought in January of 2010 fired very little.Only Selling to buy a left hand AR this is a nice gun with no problems.Has the box and all the manual.Paid $1300.00 would like $1050.00 Or would trade for a good left hande AR 15 .