SpecificationSize: 3.5mm (Suitable for 1.5-3.5mm cables); Package Includes: 5 x Ferrite Core Ring Reduce Single InterferenceThe ferrite core effectively helps in reducing electromagnetic interference(EMI) and RF interference(RFI), and get clearer signal and audio quality. Detachable and ReusableClip on wire and removable easily. It won't cause any distortion during signal transmission. Wide ApplicationMainly used for electronic connecting wire, air conditioner, PC, AC power lines, video and audio cable, telephone line, and other home appliances etc. Better ShieldingIf the wire is too thin too loose or you want get better anti-interference effect, you could wrap it around more. -Clip on ferrite bead cable can be used on all kinds of wire cords such as: Power Cord, Audio Cables, AV Cable, Data Cable, USB Cables. -It helps improving the electromagnetic field and signal quality around the cable, avoiding outside interference. -It won't cause distortion of the transmitted signal and won't affect your audio, video and picture quality. Note: Please install them in place near the interference source. (Near the import and export of shielding case as much as possible.) If a cable has equipment that needs to be protected on both sides, install one at each end. Identifying and troubleshooting affected and offend devices are necessary for successful installation. Specification: Model: 3.5mm Color: Grey Fit Cord Diameter: 1.5mm-3.5mm (0.06"-0.14") Size: 13 x 25mm (0.51" x 0.98") (D*L) Application: Driving Recorder DVR, Audio Cable, Mouse Keyboard Cable, USB Cable, Headset Cable, etc. Package Content: 5 x RFI EMI Filters