US Patent 7630610 Loop back plug with protective dust cap

A loop back device can include a dust cap with which to protect the loop back ferrule after use to facilitate reuse of the loop back device. The dust cap can be provided at a free end of the loop back device when the loop back device is secured to a tether connector. When the loop back device is removed from the tether connector, the dust cap is removed from the free end of the device and is mounted over the ferrule to protect the loop back ferrule.