Product Name : Ferrite Core Filter; Type : Ferrite Core Noise Suppressor External Size(Approx) : 2.8 x 1.5cm / 1.1 inch x 0.6 inch (L x D); Fit Cable Diameter : 5mm / 0.197 inch Material : Plastic(Housing), Ferrite ( Core); Color : Black Net Weight : 150g Helps reduce electromagnetic interference on AC power lines. Ferrite core in black plastic housing for 5mm AC power cords. Great for noise suppression on USB, Firewire, phone, power cord, coax , audio, video, etc. Simple structure and convenient installation. Just fix it, you will get a clearer signal and faster data transmission. Package Content: 18 Ferrite Core Filters Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.