 A number of different proprietary formulations of the alloy are sold under trade names such as "MuMETAL", "Mumetall", and "Mumetal2".Mu-metal typically has relative permeability values of 80,000–100,000 compared to several thousand for ordinary steel.It is a "soft" ferromagnetic material; it has low magnetic anisotropy and magnetostriction, giving it a low coercivity so that it saturates at low magnetic fields.