1)Certified Reference Material (CRM) for Chemical Analysis -Leaded Bronze BCS CRM 374 2)Certified Reference Material (CRM) for Chemical Analysis -High Tensile Brass BCS CRM 390 3) Certified Reference Material (CRM) for Chemical Analysis -Gun Metal BCS CRM 207/2 4) Certified Reference Material (CRM) for Chemical Analysis -Copper Aluminium BCS-CRM 304/1 5) Certified Reference Material (CRM) for Chemical Analysis -Leaded Bronze BCS CRM 364