Check the listing for details. FT-300-31 Ferrite toroid core 3-inch diameter #31 Material. Condition: New. Listed at 18.99 USD. FT-300-31 Ferrite toroid core 3-inch diameter #31 Material 1 x FT-300-31| FT-300-31 Ferrite Toroid Core OD(A) = 3 in / 76.0 mm +/- 1.30 mm ID(B) = 1.55 in / 39.4 mm +/- 0.85 mm Ht(C) = 0.50 in / 12.7 mm +/- 0.50 mm 31 Material Data SheetA MZn ferrite designed specifically for EMI suppression applications from as low as 1 MHz up to 500 MHz. This material does not have the dimensional resonance limitations associated with conventional MZn ferrite materials.Available in 31 Material: Round Cable EMI Suppression Cores Round Cable Snap-Its Flat Cable EMI Suppression Cores Flat Cable Snap-Its31 Material CharacteristicsPropertyUnitSymbolValueInitial Permeability@B < 10 gaussµi1500Flux Density @ Field StrengthGauss OerstedB H3600 5Residual Flux DensityGaussBr2600Coercive ForceOerstedHc0.34Loss Factor @ Frequency10 -6 MHzTan δ/ µi20 0.1Temperature Coefficient of Initial Permeability (20 -70°C)%/°C1.3Curie Temperature°CTc>130ResistivityΩ cmρ3000