This 10-pack of SFP dust covers provides an inexpensive way to protect your network switches and fiber optic equipment from dust and contaminants, by covering the exposed and unused LC fiber optic ports.Protect your network equipment investment Simply insert the dust covers into the LC port of any SFP/SFP+ transceiver in your network switches. Made of a durable rubber, the dust covers block dirt and dust particles that could cause connection issues from getting inside your equipment. The SFPLCCAP10 dust covers are backed by a StarTech.com 2-year warranty and free lifetime technical support.