It is a heat-reflecting insulation material that possesses outstanding thermal-acoustic insulation characteristics and makes it possible to create, with a single product, structures capable of meeting current regulations on both thermal and acoustic insulation. Over-foil 2L-2 is an insulation in rolls with absolutely exclusive performance that cannot be compared to that of insulators of another nature, which depend directly on thickness to exert their insulating function. Inserted inside an air gap it reflects, without absorbing it, most of the radiant energy that strikes it, determining an increase in the insulating power of the gap itself by more than 4 times.