Tripp Lite PLC13BK BLACK color Plug-lock inserts prevent accidental disconnection of C14 plug-in power cords from C13 output receptacles. IEC 60320 plug-in electrical cords are frequently loose-fitting and are often subject to accidental disconnection during routine network maintenance. To prevent critical equipment plugs from getting knocked loose, place a Plug-lock insert over any C14 input cord and connect it to any C13 outlet. The insert strengthens the connection of the plug to the outlet, keeping critical equipment plugged-in and running during routine rack access and maintenance. Plug-lock inserts provide a no-clutter alternative to common zip-tie cord retention schemes and a low cost answer to expensive proprietary locking plug and outlet hardware. PLC13BK Plug-lock inserts ship in packages of 100.