T07 is a temperature-stable high-permeability MnZn ferrite with an initial permeability (μi) of 7000, a saturation flux density (Bs) of 420 mT at 25 °C (240 mT at 100 °C) and a Curie temperature above 140 °C. Its temperature characteristic is the flattest in the family: the temperature factor of permeability αf is −0.1 to 0.5×10⁻⁶, the hysteresis constant ηB 0.2×10⁻⁶/mT is also the lowest in the family, the relative loss factor at 100 kHz is below 12×10⁻⁶ and the coercivity (Hc) 9.6 A/m at 25 °C (6 A/m at 100 °C) — inductance and phase error are almost independent of temperature and excitation level, as required of metering- grade current transformers. Its Bs of 240 mT at 100 °C is above T06/T12, giving a slightly wider operating window. Typical applications are precision current transformers for energy metering and protection, wideband and xDSL signal transformers and low-distortion signal inductors. Within the high-permeability family T07 is the compromise between μi and temperature stability: T10/T12 (μi 10000/12000) are recommended where inductance takes priority, T05 where 310 mT of hot-state Bs is required, and T06 is sufficient for general signal transformers. It is selected for stability rather than for extreme parameter values, and suits products whose calibration cost exceeds the cost of the core.