M61H is a NiZn ferrite with an initial permeability (μi) of approx. 100, a saturation flux density (Bs) of approx. 420 mT at 25 °C (370 mT at 100 °C) and a Curie temperature above 280 °C. It shares M61's permeability step but pushes the saturation flux to 420 mT with 370 mT retained at 100 °C — greatly enlarging the flux margin of HF inductors under heavy DC bias; the loss factor stays low at 50×10⁻⁶ (1.0 and 5.0 MHz), so loss behaviour under power is equally strong. Typical uses are high-current HF inductors, wireless-charging coils and high-temperature RF power filters. Division of labour with M61: M61's near-zero temperature coefficient (approx. −2×10⁻⁶/K) suits drift-sensitive filtering and tuning; M61H accepts a slightly higher coefficient (approx. 15×10⁻⁶/K) and a slightly lower Curie point (>280 °C vs >300 °C) in exchange for the family's highest flux capability — choose M61H wherever power flows.