T10 is a very-high-permeability low-remanence MnZn ferrite with an initial permeability (μi) of 10000, a saturation flux density (Bs) of 420 mT at 25 °C (240 mT at 100 °C) and a Curie temperature above 140 °C. Its remanence (Br) of 70 mT at 25 °C (60 mT at 100 °C) is the lowest in the family and its coercivity (Hc) 8 → 6 A/m: after a DC transient or switching surge the core retains almost no magnetisation, so the ratio and phase errors of a current transformer are not offset; the relative loss factor at 100 kHz is below 15×10⁻⁶ and the hysteresis constant ηB 0.4×10⁻⁶/mT, so a common-mode choke of the same volume achieves an impedance close to that of T12. Compared with T12 the Curie temperature is raised from 110 °C to 140 °C and the 100 °C Bs from 210 mT to 240 mT, giving a wider upper operating-temperature limit. Typical applications are precision current transformers and residual-current transformers, mains-input common-mode chokes and wideband signal transformers. Within the high-permeability family T10 is the temperature-tolerant low-remanence counterpart of T12: T12 (μi 12000) is recommended where the μi ceiling takes priority in a moderate environment, T07 where temperature stability takes priority and T05 where hot-state Bs is required. The μi tolerance is ±30 %; where inductance accuracy is critical, fine adjustment by turns or gap is advised.