Ferrite Toroids

https://www.magnetic-cube.com/products/magnetic-toroids-mft-23-43.html
suppression in the 20 MHz to 250 MHz range
52 Material Ferrite Toroids: The 52 Material ferrite toroid core which is made of a new NiZn Ferrite material, combines a high saturation flux density and a high Curie temperature. It is used for EMI/RFI suppression in the 200 MHz to 1 GHz range.
61 Material Ferrite Toroids: The 61 Material ferrite toroid core is designed for inductive applications up to 25mhz and also suppresses noise frequencies from 200MHz to 1000 MHz.