Magnetic shielding film MCF5 3 Linear Feet Length 3 feet ; Width: 1.96 inch Attenuation LF magnetic field: 30 dB (97 %) ; Attenuation HF: 40 dB at 1 GHz Weight: 180 g/m; Material thickness: 0.02 mm; Color: Silver Permeability:  4 = 25,000;  max. = 100,000; Saturation polarization: 0.55 T Composition: Co69, Fe4, Mo4, Nb1, Si16, B7