Retro Arms Model 10 line is a unique take on a AR PCC style upper. Mod 10 includes - A1 upper with rock river parts installed. Retro-Arms 1:10 barrel. OEM Low Dome Hand Guard with RA made flip up sight including heat shield. And Finished with a KAK Big Hole muzzle brake. Finishes include Mag phosphate for steel parts and Class III anodize for aluminum parts.