About the product:The ferrite ring core are widely applied for various wire cords, such as AC power lines, USB cable, mouse cable, keyboard cable, headset cable, video cable, data cable, etc.. Excellent for reducing high frequency interference caused by home appliances and electronics.Good Choice for you:•The core ring is made of plastic housing and ferrite core, with inner self-adaption clip can mount on cables tightly for long term use.•To stop EMI and RFI effectively that create a clearer signal and faster data transmission for you.Specification:Size: 7mm (Suitable for 5.0-7.0mm cables); Color: Black;In the package of: 10pcs x Ferrite Ring Core.Easy to install:There is small clip-on the core, so it can be opened and clipped on to a cable easily.Tips: Please install them in place near the interference source.