Product description Specification: RJ45 Anti Dust Cover: Fit for: for RJ45 Female Jack Color: Black Material: Silicone Quantity: 10pcs Overal Size: 12 x 10 x 7mm/0.5'' x 0.4'' X 0.28"(L*W*H) Designed to fit into ethernet port RJ45, just plug into the empty ethernet ports of the hub, no screws or other tools needed, easy to put on and take off, keep the dust out of the port, especially for products placed in a dusty environment.