The graphene based metal-insulator-metal (MIM) metamaterial is numerically investigated to realize an active and adjustable multi-band perfect absorber. which is composed of an asymmetric double T-shaped cavity on the top layer. As the symmetry of T-shaped cavities is broken. the previous dual-band absorption will be converted to tri-band absorber. https://www.eleanorscholz.com/product-category/wands/