It is an expansion joint made up of two opposing L-shaped profiles in natural aluminum joined together by an expanding part in vinyl resin / rubber. The opposing “L”-shaped profiles are equipped with perforated flaps which guarantee their perfect anchoring to the support; the dilating part in vinyl resin / rubber has a high resistance to mechanical, chemical, UV rays, fungi and bacteria. JOINTS in natural aluminum are suitable in all environments where mechanical and chemical stresses are expected.