One FT240-31 Toroid Ferrite Core Fair-Rite Brand Frequency Range: 1 - 300MHz EMI Suppression 1 - 500 MHz OD = 2.40 in / 61.0 mm +/- 1.30 mm ID = 1.40 in / 35.55 mm +/- 0.85 mm Ht = 0.50 in / 12.7 mm +/- 0.50 mm From bulk packaging, not in retail packaging