Aero Precision AR15A4 20" barrel military rifle setup. has full auto bolt USGI , ambidextrous charging handle,retro M16A1 style, or convert to A4 style, lots of extra parts, pins, springs, A1 and A4 pistol grip, AR15A1 and A4 handguards, A1 and A4 forward asissts, sling, range case, armorer's tools, 12 function AR wrench, punch drive pins, 2 vises blocks, hand guard removal tool, USGI cleaning kit.