Ferrite Core Products All Ferrite Ring Toroid Cores FT Mix 31 - RFI Range: 1-300 MHz FT Mix 61 - RFI Range: 200-2000 MHz FT Mix 75 - RFI Range: .15-10 MHz AC Cable Noise Filter for Large Plugs - 3" ID 44.95 USD DC Cable Noise Filter for Large Gauge Wire - 3" ID 44.95 USD