For best performance choose the smallest size that will fit your cable For USB this is 5mm, or 7mm for USB3 Alternatively you can loop thinner cables through the ferrite more than once
I supply genuine TDK products sourced from an authorised UK distributor.
TDK clip on ferrite beads for EMI/RFI noise reduction. Various sizes available. Genuine TDK product sourced from an authorised UK distributor.