Tripp Lite's DTEL2 surge suppressor is designed to protect data and communications equipment against AC transients caused by electrostatic discharge and ground surges that can enter equipment from the signal lines or chassis ground. The DTEL2 features RJ45/RJ11 plugs for modems, telephone lines and answering or fax machines. Protects against the effects of electrostatic discharge Comes with RJ11 telephone patch cable