The CAR kit comes with our A-3 standard flat-top upper, lower parts kit, and your choice of A-2 Buttstock or CAR stock (pictured). Available with HBAR or Light Weight contour barrel. 5.56 NATO Chamber and bore, Carrier is chrome lined, made from Carpenter 158 steel, and coated per mil spec. Carrier key is chrome lined and stake per mil spec. ALL Parts made in the U.S.A.